diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3cb8302cdc..8f538b1a1a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -40,9 +40,13 @@ and this project adheres to
 - all: Upgrade cosmjs-types to 0.5 ([#1131]).
 - @cosmjs/stargate: Change `packetCommitment` parameter `sequence` type from
   `Long` to `number` ([#1168]).
+- @cosmjs/tendermint-rpc: The type of `votingPower` fields was changed from
+  `number` to `bigint` as those values can exceed the safe integer range
+  ([#1133]).
 
 [#1131]: https://github.com/cosmos/cosmjs/pull/1131
 [#1168]: https://github.com/cosmos/cosmjs/pull/1168
+[#1133]: https://github.com/cosmos/cosmjs/issues/1133
 
 ## [0.28.9] - 2022-06-21
 
diff --git a/packages/tendermint-rpc/src/inthelpers.spec.ts b/packages/tendermint-rpc/src/inthelpers.spec.ts
new file mode 100644
index 0000000000..3c2a065e94
--- /dev/null
+++ b/packages/tendermint-rpc/src/inthelpers.spec.ts
@@ -0,0 +1,40 @@
+import { apiToBigInt } from "./inthelpers";
+
+describe("inthelpers", () => {
+  describe("apiToBigInt", () => {
+    it("works for positive an negative ints", () => {
+      expect(apiToBigInt("0")).toEqual(BigInt(0));
+      expect(apiToBigInt("1")).toEqual(BigInt(1));
+      expect(apiToBigInt("100")).toEqual(BigInt(100));
+      expect(apiToBigInt("-1")).toEqual(BigInt(-1));
+      expect(apiToBigInt("-100")).toEqual(BigInt(-100));
+      expect(apiToBigInt("9007199254740991")).toEqual(BigInt(9007199254740991));
+      expect(apiToBigInt("-9007199254740991")).toEqual(BigInt(-9007199254740991));
+      // uint64 max
+      expect(apiToBigInt("18446744073709551615")).toEqual(BigInt("18446744073709551615"));
+      // int64 min/max
+      expect(apiToBigInt("-9223372036854775808")).toEqual(BigInt("-9223372036854775808"));
+      expect(apiToBigInt("9223372036854775807")).toEqual(BigInt("9223372036854775807"));
+    });
+
+    it("throws for ill-formatted inputs", () => {
+      // empty
+      expect(() => apiToBigInt("")).toThrowError(/invalid string format/i);
+      expect(() => apiToBigInt("-")).toThrowError(/invalid string format/i);
+
+      // non decimal representation
+      expect(() => apiToBigInt("0x0")).toThrowError(/invalid string format/i);
+      expect(() => apiToBigInt("0x01")).toThrowError(/invalid string format/i);
+      expect(() => apiToBigInt("0x")).toThrowError(/invalid string format/i);
+
+      // decimal points
+      expect(() => apiToBigInt("1.0")).toThrowError(/invalid string format/i);
+
+      // Invalid dashes
+      expect(() => apiToBigInt("1-")).toThrowError(/invalid string format/i);
+      expect(() => apiToBigInt("--1")).toThrowError(/invalid string format/i);
+      expect(() => apiToBigInt("1-1")).toThrowError(/invalid string format/i);
+      expect(() => apiToBigInt("-1-1")).toThrowError(/invalid string format/i);
+    });
+  });
+});
diff --git a/packages/tendermint-rpc/src/inthelpers.ts b/packages/tendermint-rpc/src/inthelpers.ts
new file mode 100644
index 0000000000..77be2e2e2f
--- /dev/null
+++ b/packages/tendermint-rpc/src/inthelpers.ts
@@ -0,0 +1,36 @@
+import { Int53 } from "@cosmjs/math";
+
+import { assertString } from "./tendermint34/encodings";
+
+/**
+ * Takes an integer value from the Tendermint RPC API and
+ * returns it as number.
+ *
+ * Only works within the safe integer range.
+ */
+export function apiToSmallInt(input: string | number): number {
+  const asInt = typeof input === "number" ? new Int53(input) : Int53.fromString(input);
+  return asInt.toNumber();
+}
+
+/**
+ * Takes an integer value from the Tendermint RPC API and
+ * returns it as BigInt.
+ *
+ * This supports the full uint64 and int64 ranges.
+ */
+export function apiToBigInt(input: string): bigint {
+  assertString(input); // Runtime check on top of TypeScript just to be safe for semi-trusted API types
+  if (!input.match(/^-?[0-9]+$/)) {
+    throw new Error("Invalid string format");
+  }
+  return BigInt(input);
+}
+
+/**
+ * Takes an integer in the safe integer range and returns
+ * a string representation to be used in the Tendermint RPC API.
+ */
+export function smallIntToApi(num: number): string {
+  return new Int53(num).toString();
+}
diff --git a/packages/tendermint-rpc/src/tendermint34/adaptor/requests.ts b/packages/tendermint-rpc/src/tendermint34/adaptor/requests.ts
index 1dc959473b..ae2bd709d8 100644
--- a/packages/tendermint-rpc/src/tendermint34/adaptor/requests.ts
+++ b/packages/tendermint-rpc/src/tendermint34/adaptor/requests.ts
@@ -2,8 +2,9 @@
 import { toBase64, toHex } from "@cosmjs/encoding";
 import { JsonRpcRequest } from "@cosmjs/json-rpc";
 
+import { smallIntToApi } from "../../inthelpers";
 import { createJsonRpcRequest } from "../../jsonrpc";
-import { assertNotEmpty, Integer, may } from "../encodings";
+import { assertNotEmpty, may } from "../encodings";
 import * as requests from "../requests";
 
 interface HeightParam {
@@ -14,7 +15,7 @@ interface RpcHeightParam {
 }
 function encodeHeightParam(param: HeightParam): RpcHeightParam {
   return {
-    height: may(Integer.encode, param.height),
+    height: may(smallIntToApi, param.height),
   };
 }
 
@@ -25,8 +26,8 @@ interface RpcBlockchainRequestParams {
 
 function encodeBlockchainRequestParams(param: requests.BlockchainRequestParams): RpcBlockchainRequestParams {
   return {
-    minHeight: may(Integer.encode, param.minHeight),
-    maxHeight: may(Integer.encode, param.maxHeight),
+    minHeight: may(smallIntToApi, param.minHeight),
+    maxHeight: may(smallIntToApi, param.maxHeight),
   };
 }
 
@@ -39,8 +40,8 @@ interface RpcBlockSearchParams {
 function encodeBlockSearchParams(params: requests.BlockSearchParams): RpcBlockSearchParams {
   return {
     query: params.query,
-    page: may(Integer.encode, params.page),
-    per_page: may(Integer.encode, params.per_page),
+    page: may(smallIntToApi, params.page),
+    per_page: may(smallIntToApi, params.per_page),
     order_by: params.order_by,
   };
 }
@@ -57,7 +58,7 @@ function encodeAbciQueryParams(params: requests.AbciQueryParams): RpcAbciQueryPa
   return {
     path: assertNotEmpty(params.path),
     data: toHex(params.data),
-    height: may(Integer.encode, params.height),
+    height: may(smallIntToApi, params.height),
     prove: params.prove,
   };
 }
@@ -95,8 +96,8 @@ function encodeTxSearchParams(params: requests.TxSearchParams): RpcTxSearchParam
   return {
     query: params.query,
     prove: params.prove,
-    page: may(Integer.encode, params.page),
-    per_page: may(Integer.encode, params.per_page),
+    page: may(smallIntToApi, params.page),
+    per_page: may(smallIntToApi, params.per_page),
     order_by: params.order_by,
   };
 }
@@ -108,9 +109,9 @@ interface RpcValidatorsParams {
 }
 function encodeValidatorsParams(params: requests.ValidatorsParams): RpcValidatorsParams {
   return {
-    height: may(Integer.encode, params.height),
-    page: may(Integer.encode, params.page),
-    per_page: may(Integer.encode, params.per_page),
+    height: may(smallIntToApi, params.height),
+    page: may(smallIntToApi, params.page),
+    per_page: may(smallIntToApi, params.per_page),
   };
 }
 
diff --git a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts
index 0ad26490ab..7de09654d0 100644
--- a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts
+++ b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.spec.ts
@@ -44,7 +44,7 @@ describe("Adaptor Responses", () => {
       });
       expect(validator).toEqual({
         address: fromHex("A03DC128D38DB0BC5F18AE1872F1CB2E1FD41157"),
-        votingPower: 169980,
+        votingPower: BigInt(169980),
         pubkey: {
           algorithm: "ed25519",
           data: fromBase64("2BX6Zuj8RmdJAkD1BAg6KB0v04liyM7jBdwOGIb9F9Q="),
@@ -72,7 +72,7 @@ describe("Adaptor Responses", () => {
           algorithm: "ed25519",
           data: fromBase64("0kNlxBMpm+5WtfHIG1xsWatOXTKPLtmSqn3EiEIDZeI="),
         },
-        votingPower: 11418237,
+        votingPower: BigInt(11418237),
       });
     });
 
@@ -93,7 +93,7 @@ describe("Adaptor Responses", () => {
           algorithm: "ed25519",
           data: fromBase64("HjSC7VkhKih6xMhudlqfaFE8ZZnP8RKJPv4iqR7RhcE="),
         },
-        votingPower: 0,
+        votingPower: BigInt(0),
       });
     });
   });
@@ -116,7 +116,7 @@ describe("Adaptor Responses", () => {
           algorithm: "ed25519",
           data: fromBase64("0kNlxBMpm+5WtfHIG1xsWatOXTKPLtmSqn3EiEIDZeI="),
         },
-        votingPower: 11228980,
+        votingPower: BigInt(11228980),
         proposerPriority: 62870960,
       });
     });
diff --git a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts
index 1a44a10e15..e522294442 100644
--- a/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts
+++ b/packages/tendermint-rpc/src/tendermint34/adaptor/responses.ts
@@ -4,6 +4,7 @@ import { JsonRpcSuccessResponse } from "@cosmjs/json-rpc";
 import { assert } from "@cosmjs/utils";
 
 import { DateWithNanoseconds, fromRfc3339WithNanoseconds } from "../../dates";
+import { apiToBigInt, apiToSmallInt } from "../../inthelpers";
 import { SubscriptionEvent } from "../../rpcclients";
 import { BlockIdFlag, CommitSignature, ValidatorPubkey } from "../../types";
 import {
@@ -15,7 +16,6 @@ import {
   assertSet,
   assertString,
   dictionaryToStringMap,
-  Integer,
   may,
 } from "../encodings";
 import { hashTx } from "../hasher";
@@ -35,7 +35,7 @@ interface RpcAbciInfoResponse {
 function decodeAbciInfo(data: RpcAbciInfoResponse): responses.AbciInfoResponse {
   return {
     data: data.data,
-    lastBlockHeight: may(Integer.parse, data.last_block_height),
+    lastBlockHeight: may(apiToSmallInt, data.last_block_height),
     lastBlockAppHash: may(fromBase64, data.last_block_app_hash),
   };
 }
@@ -96,10 +96,10 @@ function decodeAbciQuery(data: RpcAbciQueryResponse): responses.AbciQueryRespons
     key: fromBase64(assertString(data.key ?? "")),
     value: fromBase64(assertString(data.value ?? "")),
     proof: may(decodeQueryProof, data.proofOps),
-    height: may(Integer.parse, data.height),
-    code: may(Integer.parse, data.code),
+    height: may(apiToSmallInt, data.height),
+    code: may(apiToSmallInt, data.code),
     codespace: assertString(data.codespace ?? ""),
-    index: may(Integer.parse, data.index),
+    index: may(apiToSmallInt, data.index),
     log: data.log,
     info: assertString(data.info ?? ""),
   };
@@ -153,13 +153,13 @@ interface RpcTxData {
 
 function decodeTxData(data: RpcTxData): responses.TxData {
   return {
-    code: Integer.parse(assertNumber(data.code ?? 0)),
+    code: apiToSmallInt(assertNumber(data.code ?? 0)),
     codeSpace: data.codespace,
     log: data.log,
     data: may(fromBase64, data.data),
     events: data.events ? decodeEvents(data.events) : [],
-    gasWanted: Integer.parse(data.gas_wanted ?? "0"),
-    gasUsed: Integer.parse(data.gas_used ?? "0"),
+    gasWanted: apiToSmallInt(data.gas_wanted ?? "0"),
+    gasUsed: apiToSmallInt(data.gas_used ?? "0"),
   };
 }
 
@@ -221,8 +221,8 @@ interface RpcBlockParams {
  */
 function decodeBlockParams(data: RpcBlockParams): responses.BlockParams {
   return {
-    maxBytes: Integer.parse(assertNotEmpty(data.max_bytes)),
-    maxGas: Integer.parse(assertNotEmpty(data.max_gas)),
+    maxBytes: apiToSmallInt(assertNotEmpty(data.max_bytes)),
+    maxGas: apiToSmallInt(assertNotEmpty(data.max_gas)),
   };
 }
 
@@ -233,8 +233,8 @@ interface RpcEvidenceParams {
 
 function decodeEvidenceParams(data: RpcEvidenceParams): responses.EvidenceParams {
   return {
-    maxAgeNumBlocks: Integer.parse(assertNotEmpty(data.max_age_num_blocks)),
-    maxAgeDuration: Integer.parse(assertNotEmpty(data.max_age_duration)),
+    maxAgeNumBlocks: apiToSmallInt(assertNotEmpty(data.max_age_num_blocks)),
+    maxAgeDuration: apiToSmallInt(assertNotEmpty(data.max_age_duration)),
   };
 }
 
@@ -279,7 +279,7 @@ interface RpcValidatorUpdate {
 export function decodeValidatorUpdate(data: RpcValidatorUpdate): responses.ValidatorUpdate {
   return {
     pubkey: decodePubkey(assertObject(data.pub_key)),
-    votingPower: Integer.parse(data.power ?? 0),
+    votingPower: apiToBigInt(data.power ?? "0"),
   };
 }
 
@@ -294,7 +294,7 @@ interface RpcBlockResultsResponse {
 
 function decodeBlockResults(data: RpcBlockResultsResponse): responses.BlockResultsResponse {
   return {
-    height: Integer.parse(assertNotEmpty(data.height)),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
     results: (data.txs_results || []).map(decodeTxData),
     validatorUpdates: (data.validator_updates || []).map(decodeValidatorUpdate),
     consensusUpdates: may(decodeConsensusParams, data.consensus_param_updates),
@@ -330,8 +330,8 @@ interface RpcBlockVersion {
 
 function decodeBlockVersion(data: RpcBlockVersion): responses.Version {
   return {
-    block: Integer.parse(data.block),
-    app: Integer.parse(data.app ?? 0),
+    block: apiToSmallInt(data.block),
+    app: apiToSmallInt(data.app ?? 0),
   };
 }
 
@@ -369,7 +369,7 @@ function decodeHeader(data: RpcHeader): responses.Header {
   return {
     version: decodeBlockVersion(data.version),
     chainId: assertNotEmpty(data.chain_id),
-    height: Integer.parse(assertNotEmpty(data.height)),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
     time: fromRfc3339WithNanoseconds(assertNotEmpty(data.time)),
 
     // When there is no last block ID (i.e. this block's height is 1), we get an empty structure like this:
@@ -400,9 +400,9 @@ interface RpcBlockMeta {
 function decodeBlockMeta(data: RpcBlockMeta): responses.BlockMeta {
   return {
     blockId: decodeBlockId(data.block_id),
-    blockSize: Integer.parse(assertNotEmpty(data.block_size)),
+    blockSize: apiToSmallInt(assertNotEmpty(data.block_size)),
     header: decodeHeader(data.header),
-    numTxs: Integer.parse(assertNotEmpty(data.num_txs)),
+    numTxs: apiToSmallInt(assertNotEmpty(data.num_txs)),
   };
 }
 
@@ -413,7 +413,7 @@ interface RpcBlockchainResponse {
 
 function decodeBlockchain(data: RpcBlockchainResponse): responses.BlockchainResponse {
   return {
-    lastHeight: Integer.parse(assertNotEmpty(data.last_height)),
+    lastHeight: apiToSmallInt(assertNotEmpty(data.last_height)),
     blockMetas: assertArray(data.block_metas).map(decodeBlockMeta),
   };
 }
@@ -440,7 +440,7 @@ interface RpcBroadcastTxCommitResponse {
 
 function decodeBroadcastTxCommit(data: RpcBroadcastTxCommitResponse): responses.BroadcastTxCommitResponse {
   return {
-    height: Integer.parse(data.height),
+    height: apiToSmallInt(data.height),
     hash: fromHex(assertNotEmpty(data.hash)),
     checkTx: decodeTxData(assertObject(data.check_tx)),
     deliverTx: may(decodeTxData, data.deliver_tx),
@@ -494,8 +494,8 @@ interface RpcCommit {
 function decodeCommit(data: RpcCommit): responses.Commit {
   return {
     blockId: decodeBlockId(assertObject(data.block_id)),
-    height: Integer.parse(assertNotEmpty(data.height)),
-    round: Integer.parse(data.round),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
+    round: apiToSmallInt(data.round),
     signatures: assertArray(data.signatures).map(decodeCommitSignature),
   };
 }
@@ -528,7 +528,7 @@ export function decodeValidatorGenesis(data: RpcValidatorGenesis): responses.Val
   return {
     address: fromHex(assertNotEmpty(data.address)),
     pubkey: decodePubkey(assertObject(data.pub_key)),
-    votingPower: Integer.parse(assertNotEmpty(data.power)),
+    votingPower: apiToBigInt(assertNotEmpty(data.power)),
   };
 }
 
@@ -571,9 +571,9 @@ interface RpcValidatorInfo {
 export function decodeValidatorInfo(data: RpcValidatorInfo): responses.Validator {
   return {
     pubkey: decodePubkey(assertObject(data.pub_key)),
-    votingPower: Integer.parse(assertNotEmpty(data.voting_power)),
+    votingPower: apiToBigInt(assertNotEmpty(data.voting_power)),
     address: fromHex(assertNotEmpty(data.address)),
-    proposerPriority: data.proposer_priority ? Integer.parse(data.proposer_priority) : undefined,
+    proposerPriority: data.proposer_priority ? apiToSmallInt(data.proposer_priority) : undefined,
   };
 }
 
@@ -611,9 +611,9 @@ function decodeNodeInfo(data: RpcNodeInfo): responses.NodeInfo {
     moniker: assertNotEmpty(data.moniker),
     other: dictionaryToStringMap(data.other),
     protocolVersion: {
-      app: Integer.parse(assertNotEmpty(data.protocol_version.app)),
-      block: Integer.parse(assertNotEmpty(data.protocol_version.block)),
-      p2p: Integer.parse(assertNotEmpty(data.protocol_version.p2p)),
+      app: apiToSmallInt(assertNotEmpty(data.protocol_version.app)),
+      block: apiToSmallInt(assertNotEmpty(data.protocol_version.block)),
+      p2p: apiToSmallInt(assertNotEmpty(data.protocol_version.p2p)),
     },
   };
 }
@@ -633,7 +633,7 @@ function decodeSyncInfo(data: RpcSyncInfo): responses.SyncInfo {
     latestBlockHash: fromHex(assertNotEmpty(data.latest_block_hash)),
     latestAppHash: fromHex(assertNotEmpty(data.latest_app_hash)),
     latestBlockTime: fromRfc3339WithNanoseconds(assertNotEmpty(data.latest_block_time)),
-    latestBlockHeight: Integer.parse(assertNotEmpty(data.latest_block_height)),
+    latestBlockHeight: apiToSmallInt(assertNotEmpty(data.latest_block_height)),
     catchingUp: assertBoolean(data.catching_up),
   };
 }
@@ -685,8 +685,8 @@ function decodeTxProof(data: RpcTxProof): responses.TxProof {
     data: fromBase64(assertNotEmpty(data.data)),
     rootHash: fromHex(assertNotEmpty(data.root_hash)),
     proof: {
-      total: Integer.parse(assertNotEmpty(data.proof.total)),
-      index: Integer.parse(assertNotEmpty(data.proof.index)),
+      total: apiToSmallInt(assertNotEmpty(data.proof.total)),
+      index: apiToSmallInt(assertNotEmpty(data.proof.index)),
       leafHash: fromBase64(assertNotEmpty(data.proof.leaf_hash)),
       aunts: assertArray(data.proof.aunts).map(fromBase64),
     },
@@ -708,8 +708,8 @@ function decodeTxResponse(data: RpcTxResponse): responses.TxResponse {
   return {
     tx: fromBase64(assertNotEmpty(data.tx)),
     result: decodeTxData(assertObject(data.tx_result)),
-    height: Integer.parse(assertNotEmpty(data.height)),
-    index: Integer.parse(assertNumber(data.index)),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
+    index: apiToSmallInt(assertNumber(data.index)),
     hash: fromHex(assertNotEmpty(data.hash)),
     proof: may(decodeTxProof, data.proof),
   };
@@ -722,7 +722,7 @@ interface RpcTxSearchResponse {
 
 function decodeTxSearch(data: RpcTxSearchResponse): responses.TxSearchResponse {
   return {
-    totalCount: Integer.parse(assertNotEmpty(data.total_count)),
+    totalCount: apiToSmallInt(assertNotEmpty(data.total_count)),
     txs: assertArray(data.txs).map(decodeTxResponse),
   };
 }
@@ -742,8 +742,8 @@ function decodeTxEvent(data: RpcTxEvent): responses.TxEvent {
     tx: tx,
     hash: hashTx(tx),
     result: decodeTxData(data.result),
-    height: Integer.parse(assertNotEmpty(data.height)),
-    index: may(Integer.parse, data.index),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
+    index: may(apiToSmallInt, data.index),
   };
 }
 
@@ -756,10 +756,10 @@ interface RpcValidatorsResponse {
 
 function decodeValidators(data: RpcValidatorsResponse): responses.ValidatorsResponse {
   return {
-    blockHeight: Integer.parse(assertNotEmpty(data.block_height)),
+    blockHeight: apiToSmallInt(assertNotEmpty(data.block_height)),
     validators: assertArray(data.validators).map(decodeValidatorInfo),
-    count: Integer.parse(assertNotEmpty(data.count)),
-    total: Integer.parse(assertNotEmpty(data.total)),
+    count: apiToSmallInt(assertNotEmpty(data.count)),
+    total: apiToSmallInt(assertNotEmpty(data.total)),
   };
 }
 
@@ -813,7 +813,7 @@ interface RpcBlockSearchResponse {
 
 function decodeBlockSearch(data: RpcBlockSearchResponse): responses.BlockSearchResponse {
   return {
-    totalCount: Integer.parse(assertNotEmpty(data.total_count)),
+    totalCount: apiToSmallInt(assertNotEmpty(data.total_count)),
     blocks: assertArray(data.blocks).map(decodeBlockResponse),
   };
 }
@@ -825,8 +825,8 @@ interface RpcNumUnconfirmedTxsResponse {
 
 function decodeNumUnconfirmedTxs(data: RpcNumUnconfirmedTxsResponse): responses.NumUnconfirmedTxsResponse {
   return {
-    total: Integer.parse(assertNotEmpty(data.total)),
-    totalBytes: Integer.parse(assertNotEmpty(data.total_bytes)),
+    total: apiToSmallInt(assertNotEmpty(data.total)),
+    totalBytes: apiToSmallInt(assertNotEmpty(data.total_bytes)),
   };
 }
 
diff --git a/packages/tendermint-rpc/src/tendermint34/encodings.spec.ts b/packages/tendermint-rpc/src/tendermint34/encodings.spec.ts
index afea0600d3..b4921d3b73 100644
--- a/packages/tendermint-rpc/src/tendermint34/encodings.spec.ts
+++ b/packages/tendermint-rpc/src/tendermint34/encodings.spec.ts
@@ -1,6 +1,13 @@
 import { ReadonlyDate } from "readonly-date";
 
-import { encodeBlockId, encodeBytes, encodeInt, encodeString, encodeTime, encodeVersion } from "./encodings";
+import {
+  encodeBlockId,
+  encodeBytes,
+  encodeString,
+  encodeTime,
+  encodeUvarint,
+  encodeVersion,
+} from "./encodings";
 
 describe("encodings", () => {
   describe("encodeString", () => {
@@ -13,14 +20,14 @@ describe("encodings", () => {
     });
   });
 
-  describe("encodeInt", () => {
+  describe("encodeUvarint", () => {
     it("works", () => {
-      expect(encodeInt(0)).toEqual(Uint8Array.from([0]));
-      expect(encodeInt(1)).toEqual(Uint8Array.from([1]));
-      expect(encodeInt(127)).toEqual(Uint8Array.from([127]));
-      expect(encodeInt(128)).toEqual(Uint8Array.from([128, 1]));
-      expect(encodeInt(255)).toEqual(Uint8Array.from([255, 1]));
-      expect(encodeInt(256)).toEqual(Uint8Array.from([128, 2]));
+      expect(encodeUvarint(0)).toEqual(Uint8Array.from([0]));
+      expect(encodeUvarint(1)).toEqual(Uint8Array.from([1]));
+      expect(encodeUvarint(127)).toEqual(Uint8Array.from([127]));
+      expect(encodeUvarint(128)).toEqual(Uint8Array.from([128, 1]));
+      expect(encodeUvarint(255)).toEqual(Uint8Array.from([255, 1]));
+      expect(encodeUvarint(256)).toEqual(Uint8Array.from([128, 2]));
     });
   });
 
diff --git a/packages/tendermint-rpc/src/tendermint34/encodings.ts b/packages/tendermint-rpc/src/tendermint34/encodings.ts
index ec5b072775..037b506898 100644
--- a/packages/tendermint-rpc/src/tendermint34/encodings.ts
+++ b/packages/tendermint-rpc/src/tendermint34/encodings.ts
@@ -1,5 +1,4 @@
 import { toUtf8 } from "@cosmjs/encoding";
-import { Int53 } from "@cosmjs/math";
 
 import { ReadonlyDateWithNanoseconds } from "../dates";
 import { BlockId, Version } from "./responses";
@@ -140,17 +139,6 @@ export function dictionaryToStringMap(obj: Record<string, unknown>): Map<string,
   return out;
 }
 
-export class Integer {
-  public static parse(input: string | number): number {
-    const asInt = typeof input === "number" ? new Int53(input) : Int53.fromString(input);
-    return asInt.toNumber();
-  }
-
-  public static encode(num: number): string {
-    return new Int53(num).toString();
-  }
-}
-
 // Encodings needed for hashing block headers
 // Several of these functions are inspired by https://github.com/nomic-io/js-tendermint/blob/tendermint-0.30/src/
 
@@ -161,18 +149,21 @@ export function encodeString(s: string): Uint8Array {
 }
 
 // See https://github.com/tendermint/go-amino/blob/v0.15.0/encoder.go#L79-L87
-export function encodeInt(n: number): Uint8Array {
-  // eslint-disable-next-line no-bitwise
-  return n >= 0x80 ? Uint8Array.from([(n & 0xff) | 0x80, ...encodeInt(n >> 7)]) : Uint8Array.from([n & 0xff]);
+export function encodeUvarint(n: number): Uint8Array {
+  return n >= 0x80
+    ? // eslint-disable-next-line no-bitwise
+      Uint8Array.from([(n & 0xff) | 0x80, ...encodeUvarint(n >> 7)])
+    : // eslint-disable-next-line no-bitwise
+      Uint8Array.from([n & 0xff]);
 }
 
 // See https://github.com/tendermint/go-amino/blob/v0.15.0/encoder.go#L134-L178
 export function encodeTime(time: ReadonlyDateWithNanoseconds): Uint8Array {
   const milliseconds = time.getTime();
   const seconds = Math.floor(milliseconds / 1000);
-  const secondsArray = seconds ? [0x08, ...encodeInt(seconds)] : new Uint8Array();
+  const secondsArray = seconds ? [0x08, ...encodeUvarint(seconds)] : new Uint8Array();
   const nanoseconds = (time.nanoseconds || 0) + (milliseconds % 1000) * 1e6;
-  const nanosecondsArray = nanoseconds ? [0x10, ...encodeInt(nanoseconds)] : new Uint8Array();
+  const nanosecondsArray = nanoseconds ? [0x10, ...encodeUvarint(nanoseconds)] : new Uint8Array();
   return Uint8Array.from([...secondsArray, ...nanosecondsArray]);
 }
 
@@ -184,8 +175,10 @@ export function encodeBytes(bytes: Uint8Array): Uint8Array {
 }
 
 export function encodeVersion(version: Version): Uint8Array {
-  const blockArray = version.block ? Uint8Array.from([0x08, ...encodeInt(version.block)]) : new Uint8Array();
-  const appArray = version.app ? Uint8Array.from([0x10, ...encodeInt(version.app)]) : new Uint8Array();
+  const blockArray = version.block
+    ? Uint8Array.from([0x08, ...encodeUvarint(version.block)])
+    : new Uint8Array();
+  const appArray = version.app ? Uint8Array.from([0x10, ...encodeUvarint(version.app)]) : new Uint8Array();
   return Uint8Array.from([...blockArray, ...appArray]);
 }
 
diff --git a/packages/tendermint-rpc/src/tendermint34/hasher.ts b/packages/tendermint-rpc/src/tendermint34/hasher.ts
index 65ba6627be..a02d2f814f 100644
--- a/packages/tendermint-rpc/src/tendermint34/hasher.ts
+++ b/packages/tendermint-rpc/src/tendermint34/hasher.ts
@@ -1,6 +1,13 @@
 import { Sha256, sha256 } from "@cosmjs/crypto";
 
-import { encodeBlockId, encodeBytes, encodeInt, encodeString, encodeTime, encodeVersion } from "./encodings";
+import {
+  encodeBlockId,
+  encodeBytes,
+  encodeString,
+  encodeTime,
+  encodeUvarint,
+  encodeVersion,
+} from "./encodings";
 import { Header } from "./responses";
 
 // hash is sha256
@@ -55,7 +62,7 @@ export function hashBlock(header: Header): Uint8Array {
   const encodedFields: readonly Uint8Array[] = [
     encodeVersion(header.version),
     encodeString(header.chainId),
-    encodeInt(header.height),
+    encodeUvarint(header.height),
     encodeTime(header.time),
     encodeBlockId(header.lastBlockId),
 
diff --git a/packages/tendermint-rpc/src/tendermint34/responses.ts b/packages/tendermint-rpc/src/tendermint34/responses.ts
index 0e82dcb3db..70a3516fb3 100644
--- a/packages/tendermint-rpc/src/tendermint34/responses.ts
+++ b/packages/tendermint-rpc/src/tendermint34/responses.ts
@@ -352,13 +352,13 @@ export interface SyncInfo {
 export interface Validator {
   readonly address: Uint8Array;
   readonly pubkey?: ValidatorPubkey;
-  readonly votingPower: number;
+  readonly votingPower: bigint;
   readonly proposerPriority?: number;
 }
 
 export interface ValidatorUpdate {
   readonly pubkey: ValidatorPubkey;
-  readonly votingPower: number;
+  readonly votingPower: bigint;
 }
 
 export interface ConsensusParams {
diff --git a/packages/tendermint-rpc/src/tendermint35/adaptor/requests.ts b/packages/tendermint-rpc/src/tendermint35/adaptor/requests.ts
index 441a4aa7a0..52a06a2932 100644
--- a/packages/tendermint-rpc/src/tendermint35/adaptor/requests.ts
+++ b/packages/tendermint-rpc/src/tendermint35/adaptor/requests.ts
@@ -2,8 +2,9 @@
 import { toBase64, toHex } from "@cosmjs/encoding";
 import { JsonRpcRequest } from "@cosmjs/json-rpc";
 
+import { smallIntToApi } from "../../inthelpers";
 import { createJsonRpcRequest } from "../../jsonrpc";
-import { assertNotEmpty, Integer, may } from "../encodings";
+import { assertNotEmpty, may } from "../encodings";
 import * as requests from "../requests";
 
 interface HeightParam {
@@ -14,7 +15,7 @@ interface RpcHeightParam {
 }
 function encodeHeightParam(param: HeightParam): RpcHeightParam {
   return {
-    height: may(Integer.encode, param.height),
+    height: may(smallIntToApi, param.height),
   };
 }
 
@@ -25,8 +26,8 @@ interface RpcBlockchainRequestParams {
 
 function encodeBlockchainRequestParams(param: requests.BlockchainRequestParams): RpcBlockchainRequestParams {
   return {
-    minHeight: may(Integer.encode, param.minHeight),
-    maxHeight: may(Integer.encode, param.maxHeight),
+    minHeight: may(smallIntToApi, param.minHeight),
+    maxHeight: may(smallIntToApi, param.maxHeight),
   };
 }
 
@@ -39,8 +40,8 @@ interface RpcBlockSearchParams {
 function encodeBlockSearchParams(params: requests.BlockSearchParams): RpcBlockSearchParams {
   return {
     query: params.query,
-    page: may(Integer.encode, params.page),
-    per_page: may(Integer.encode, params.per_page),
+    page: may(smallIntToApi, params.page),
+    per_page: may(smallIntToApi, params.per_page),
     order_by: params.order_by,
   };
 }
@@ -57,7 +58,7 @@ function encodeAbciQueryParams(params: requests.AbciQueryParams): RpcAbciQueryPa
   return {
     path: assertNotEmpty(params.path),
     data: toHex(params.data),
-    height: may(Integer.encode, params.height),
+    height: may(smallIntToApi, params.height),
     prove: params.prove,
   };
 }
@@ -95,8 +96,8 @@ function encodeTxSearchParams(params: requests.TxSearchParams): RpcTxSearchParam
   return {
     query: params.query,
     prove: params.prove,
-    page: may(Integer.encode, params.page),
-    per_page: may(Integer.encode, params.per_page),
+    page: may(smallIntToApi, params.page),
+    per_page: may(smallIntToApi, params.per_page),
     order_by: params.order_by,
   };
 }
@@ -108,9 +109,9 @@ interface RpcValidatorsParams {
 }
 function encodeValidatorsParams(params: requests.ValidatorsParams): RpcValidatorsParams {
   return {
-    height: may(Integer.encode, params.height),
-    page: may(Integer.encode, params.page),
-    per_page: may(Integer.encode, params.per_page),
+    height: may(smallIntToApi, params.height),
+    page: may(smallIntToApi, params.page),
+    per_page: may(smallIntToApi, params.per_page),
   };
 }
 
diff --git a/packages/tendermint-rpc/src/tendermint35/adaptor/responses.spec.ts b/packages/tendermint-rpc/src/tendermint35/adaptor/responses.spec.ts
index 35e86679ea..c85b753328 100644
--- a/packages/tendermint-rpc/src/tendermint35/adaptor/responses.spec.ts
+++ b/packages/tendermint-rpc/src/tendermint35/adaptor/responses.spec.ts
@@ -44,7 +44,7 @@ describe("Adaptor Responses", () => {
       });
       expect(validator).toEqual({
         address: fromHex("A03DC128D38DB0BC5F18AE1872F1CB2E1FD41157"),
-        votingPower: 169980,
+        votingPower: BigInt(169980),
         pubkey: {
           algorithm: "ed25519",
           data: fromBase64("2BX6Zuj8RmdJAkD1BAg6KB0v04liyM7jBdwOGIb9F9Q="),
@@ -72,7 +72,7 @@ describe("Adaptor Responses", () => {
           algorithm: "ed25519",
           data: fromBase64("0kNlxBMpm+5WtfHIG1xsWatOXTKPLtmSqn3EiEIDZeI="),
         },
-        votingPower: 11418237,
+        votingPower: BigInt(11418237),
       });
     });
 
@@ -93,7 +93,7 @@ describe("Adaptor Responses", () => {
           algorithm: "ed25519",
           data: fromBase64("HjSC7VkhKih6xMhudlqfaFE8ZZnP8RKJPv4iqR7RhcE="),
         },
-        votingPower: 0,
+        votingPower: BigInt(0),
       });
     });
   });
@@ -116,7 +116,7 @@ describe("Adaptor Responses", () => {
           algorithm: "ed25519",
           data: fromBase64("0kNlxBMpm+5WtfHIG1xsWatOXTKPLtmSqn3EiEIDZeI="),
         },
-        votingPower: 11228980,
+        votingPower: BigInt(11228980),
         proposerPriority: 62870960,
       });
     });
diff --git a/packages/tendermint-rpc/src/tendermint35/adaptor/responses.ts b/packages/tendermint-rpc/src/tendermint35/adaptor/responses.ts
index 811f113520..30aad6efba 100644
--- a/packages/tendermint-rpc/src/tendermint35/adaptor/responses.ts
+++ b/packages/tendermint-rpc/src/tendermint35/adaptor/responses.ts
@@ -4,6 +4,7 @@ import { JsonRpcSuccessResponse } from "@cosmjs/json-rpc";
 import { assert } from "@cosmjs/utils";
 
 import { DateWithNanoseconds, fromRfc3339WithNanoseconds } from "../../dates";
+import { apiToBigInt, apiToSmallInt } from "../../inthelpers";
 import { SubscriptionEvent } from "../../rpcclients";
 import { BlockIdFlag, CommitSignature, ValidatorPubkey } from "../../types";
 import {
@@ -15,7 +16,6 @@ import {
   assertSet,
   assertString,
   dictionaryToStringMap,
-  Integer,
   may,
 } from "../encodings";
 import { hashTx } from "../hasher";
@@ -35,7 +35,7 @@ interface RpcAbciInfoResponse {
 function decodeAbciInfo(data: RpcAbciInfoResponse): responses.AbciInfoResponse {
   return {
     data: data.data,
-    lastBlockHeight: may(Integer.parse, data.last_block_height),
+    lastBlockHeight: may(apiToSmallInt, data.last_block_height),
     lastBlockAppHash: may(fromBase64, data.last_block_app_hash),
   };
 }
@@ -95,10 +95,10 @@ function decodeAbciQuery(data: RpcAbciQueryResponse): responses.AbciQueryRespons
     key: fromBase64(assertString(data.key ?? "")),
     value: fromBase64(assertString(data.value ?? "")),
     proof: may(decodeQueryProof, data.proofOps),
-    height: may(Integer.parse, data.height),
-    code: may(Integer.parse, data.code),
+    height: may(apiToSmallInt, data.height),
+    code: may(apiToSmallInt, data.code),
     codespace: assertString(data.codespace ?? ""),
-    index: may(Integer.parse, data.index),
+    index: may(apiToSmallInt, data.index),
     log: data.log,
     info: assertString(data.info ?? ""),
   };
@@ -154,13 +154,13 @@ interface RpcTxData {
 
 function decodeTxData(data: RpcTxData): responses.TxData {
   return {
-    code: Integer.parse(assertNumber(data.code ?? 0)),
+    code: apiToSmallInt(assertNumber(data.code ?? 0)),
     codeSpace: data.codespace,
     log: data.log,
     data: may(fromBase64, data.data),
     events: data.events ? decodeEvents(data.events) : [],
-    gasWanted: Integer.parse(data.gas_wanted ?? "0"),
-    gasUsed: Integer.parse(data.gas_used ?? "0"),
+    gasWanted: apiToSmallInt(data.gas_wanted ?? "0"),
+    gasUsed: apiToSmallInt(data.gas_used ?? "0"),
   };
 }
 
@@ -222,8 +222,8 @@ interface RpcBlockParams {
  */
 function decodeBlockParams(data: RpcBlockParams): responses.BlockParams {
   return {
-    maxBytes: Integer.parse(assertNotEmpty(data.max_bytes)),
-    maxGas: Integer.parse(assertNotEmpty(data.max_gas)),
+    maxBytes: apiToSmallInt(assertNotEmpty(data.max_bytes)),
+    maxGas: apiToSmallInt(assertNotEmpty(data.max_gas)),
   };
 }
 
@@ -234,8 +234,8 @@ interface RpcEvidenceParams {
 
 function decodeEvidenceParams(data: RpcEvidenceParams): responses.EvidenceParams {
   return {
-    maxAgeNumBlocks: Integer.parse(assertNotEmpty(data.max_age_num_blocks)),
-    maxAgeDuration: Integer.parse(assertNotEmpty(data.max_age_duration)),
+    maxAgeNumBlocks: apiToSmallInt(assertNotEmpty(data.max_age_num_blocks)),
+    maxAgeDuration: apiToSmallInt(assertNotEmpty(data.max_age_duration)),
   };
 }
 
@@ -280,7 +280,7 @@ interface RpcValidatorUpdate {
 export function decodeValidatorUpdate(data: RpcValidatorUpdate): responses.ValidatorUpdate {
   return {
     pubkey: decodePubkey(assertObject(data.pub_key)),
-    votingPower: Integer.parse(data.power ?? 0),
+    votingPower: apiToBigInt(data.power ?? "0"),
   };
 }
 
@@ -295,7 +295,7 @@ interface RpcBlockResultsResponse {
 
 function decodeBlockResults(data: RpcBlockResultsResponse): responses.BlockResultsResponse {
   return {
-    height: Integer.parse(assertNotEmpty(data.height)),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
     results: (data.txs_results || []).map(decodeTxData),
     validatorUpdates: (data.validator_updates || []).map(decodeValidatorUpdate),
     consensusUpdates: may(decodeConsensusParams, data.consensus_param_updates),
@@ -331,8 +331,8 @@ interface RpcBlockVersion {
 
 function decodeBlockVersion(data: RpcBlockVersion): responses.Version {
   return {
-    block: Integer.parse(data.block),
-    app: Integer.parse(data.app ?? 0),
+    block: apiToSmallInt(data.block),
+    app: apiToSmallInt(data.app ?? 0),
   };
 }
 
@@ -370,7 +370,7 @@ function decodeHeader(data: RpcHeader): responses.Header {
   return {
     version: decodeBlockVersion(data.version),
     chainId: assertNotEmpty(data.chain_id),
-    height: Integer.parse(assertNotEmpty(data.height)),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
     time: fromRfc3339WithNanoseconds(assertNotEmpty(data.time)),
 
     // When there is no last block ID (i.e. this block's height is 1), we get an empty structure like this:
@@ -401,9 +401,9 @@ interface RpcBlockMeta {
 function decodeBlockMeta(data: RpcBlockMeta): responses.BlockMeta {
   return {
     blockId: decodeBlockId(data.block_id),
-    blockSize: Integer.parse(assertNotEmpty(data.block_size)),
+    blockSize: apiToSmallInt(assertNotEmpty(data.block_size)),
     header: decodeHeader(data.header),
-    numTxs: Integer.parse(assertNotEmpty(data.num_txs)),
+    numTxs: apiToSmallInt(assertNotEmpty(data.num_txs)),
   };
 }
 
@@ -414,7 +414,7 @@ interface RpcBlockchainResponse {
 
 function decodeBlockchain(data: RpcBlockchainResponse): responses.BlockchainResponse {
   return {
-    lastHeight: Integer.parse(assertNotEmpty(data.last_height)),
+    lastHeight: apiToSmallInt(assertNotEmpty(data.last_height)),
     blockMetas: assertArray(data.block_metas).map(decodeBlockMeta),
   };
 }
@@ -441,7 +441,7 @@ interface RpcBroadcastTxCommitResponse {
 
 function decodeBroadcastTxCommit(data: RpcBroadcastTxCommitResponse): responses.BroadcastTxCommitResponse {
   return {
-    height: Integer.parse(data.height),
+    height: apiToSmallInt(data.height),
     hash: fromHex(assertNotEmpty(data.hash)),
     checkTx: decodeTxData(assertObject(data.check_tx)),
     deliverTx: may(decodeTxData, data.deliver_tx),
@@ -495,8 +495,8 @@ interface RpcCommit {
 function decodeCommit(data: RpcCommit): responses.Commit {
   return {
     blockId: decodeBlockId(assertObject(data.block_id)),
-    height: Integer.parse(assertNotEmpty(data.height)),
-    round: Integer.parse(data.round),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
+    round: apiToSmallInt(data.round),
     signatures: assertArray(data.signatures).map(decodeCommitSignature),
   };
 }
@@ -529,7 +529,7 @@ export function decodeValidatorGenesis(data: RpcValidatorGenesis): responses.Val
   return {
     address: fromHex(assertNotEmpty(data.address)),
     pubkey: decodePubkey(assertObject(data.pub_key)),
-    votingPower: Integer.parse(assertNotEmpty(data.power)),
+    votingPower: apiToBigInt(assertNotEmpty(data.power)),
   };
 }
 
@@ -572,9 +572,9 @@ interface RpcValidatorInfo {
 export function decodeValidatorInfo(data: RpcValidatorInfo): responses.Validator {
   return {
     pubkey: decodePubkey(assertObject(data.pub_key)),
-    votingPower: Integer.parse(assertNotEmpty(data.voting_power)),
+    votingPower: apiToBigInt(assertNotEmpty(data.voting_power)),
     address: fromHex(assertNotEmpty(data.address)),
-    proposerPriority: data.proposer_priority ? Integer.parse(data.proposer_priority) : undefined,
+    proposerPriority: data.proposer_priority ? apiToSmallInt(data.proposer_priority) : undefined,
   };
 }
 
@@ -612,9 +612,9 @@ function decodeNodeInfo(data: RpcNodeInfo): responses.NodeInfo {
     moniker: assertNotEmpty(data.moniker),
     other: dictionaryToStringMap(data.other),
     protocolVersion: {
-      app: Integer.parse(assertNotEmpty(data.protocol_version.app)),
-      block: Integer.parse(assertNotEmpty(data.protocol_version.block)),
-      p2p: Integer.parse(assertNotEmpty(data.protocol_version.p2p)),
+      app: apiToSmallInt(assertNotEmpty(data.protocol_version.app)),
+      block: apiToSmallInt(assertNotEmpty(data.protocol_version.block)),
+      p2p: apiToSmallInt(assertNotEmpty(data.protocol_version.p2p)),
     },
   };
 }
@@ -634,7 +634,7 @@ function decodeSyncInfo(data: RpcSyncInfo): responses.SyncInfo {
     latestBlockHash: fromHex(assertNotEmpty(data.latest_block_hash)),
     latestAppHash: fromHex(assertNotEmpty(data.latest_app_hash)),
     latestBlockTime: fromRfc3339WithNanoseconds(assertNotEmpty(data.latest_block_time)),
-    latestBlockHeight: Integer.parse(assertNotEmpty(data.latest_block_height)),
+    latestBlockHeight: apiToSmallInt(assertNotEmpty(data.latest_block_height)),
     catchingUp: assertBoolean(data.catching_up),
   };
 }
@@ -686,8 +686,8 @@ function decodeTxProof(data: RpcTxProof): responses.TxProof {
     data: fromBase64(assertNotEmpty(data.data)),
     rootHash: fromHex(assertNotEmpty(data.root_hash)),
     proof: {
-      total: Integer.parse(assertNotEmpty(data.proof.total)),
-      index: Integer.parse(assertNotEmpty(data.proof.index)),
+      total: apiToSmallInt(assertNotEmpty(data.proof.total)),
+      index: apiToSmallInt(assertNotEmpty(data.proof.index)),
       leafHash: fromBase64(assertNotEmpty(data.proof.leaf_hash)),
       aunts: assertArray(data.proof.aunts).map(fromBase64),
     },
@@ -709,8 +709,8 @@ function decodeTxResponse(data: RpcTxResponse): responses.TxResponse {
   return {
     tx: fromBase64(assertNotEmpty(data.tx)),
     result: decodeTxData(assertObject(data.tx_result)),
-    height: Integer.parse(assertNotEmpty(data.height)),
-    index: Integer.parse(assertNumber(data.index)),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
+    index: apiToSmallInt(assertNumber(data.index)),
     hash: fromHex(assertNotEmpty(data.hash)),
     proof: may(decodeTxProof, data.proof),
   };
@@ -723,7 +723,7 @@ interface RpcTxSearchResponse {
 
 function decodeTxSearch(data: RpcTxSearchResponse): responses.TxSearchResponse {
   return {
-    totalCount: Integer.parse(assertNotEmpty(data.total_count)),
+    totalCount: apiToSmallInt(assertNotEmpty(data.total_count)),
     txs: assertArray(data.txs).map(decodeTxResponse),
   };
 }
@@ -743,8 +743,8 @@ function decodeTxEvent(data: RpcTxEvent): responses.TxEvent {
     tx: tx,
     hash: hashTx(tx),
     result: decodeTxData(data.result),
-    height: Integer.parse(assertNotEmpty(data.height)),
-    index: may(Integer.parse, data.index),
+    height: apiToSmallInt(assertNotEmpty(data.height)),
+    index: may(apiToSmallInt, data.index),
   };
 }
 
@@ -757,10 +757,10 @@ interface RpcValidatorsResponse {
 
 function decodeValidators(data: RpcValidatorsResponse): responses.ValidatorsResponse {
   return {
-    blockHeight: Integer.parse(assertNotEmpty(data.block_height)),
+    blockHeight: apiToSmallInt(assertNotEmpty(data.block_height)),
     validators: assertArray(data.validators).map(decodeValidatorInfo),
-    count: Integer.parse(assertNotEmpty(data.count)),
-    total: Integer.parse(assertNotEmpty(data.total)),
+    count: apiToSmallInt(assertNotEmpty(data.count)),
+    total: apiToSmallInt(assertNotEmpty(data.total)),
   };
 }
 
@@ -814,7 +814,7 @@ interface RpcBlockSearchResponse {
 
 function decodeBlockSearch(data: RpcBlockSearchResponse): responses.BlockSearchResponse {
   return {
-    totalCount: Integer.parse(assertNotEmpty(data.total_count)),
+    totalCount: apiToSmallInt(assertNotEmpty(data.total_count)),
     blocks: assertArray(data.blocks).map(decodeBlockResponse),
   };
 }
@@ -826,8 +826,8 @@ interface RpcNumUnconfirmedTxsResponse {
 
 function decodeNumUnconfirmedTxs(data: RpcNumUnconfirmedTxsResponse): responses.NumUnconfirmedTxsResponse {
   return {
-    total: Integer.parse(assertNotEmpty(data.total)),
-    totalBytes: Integer.parse(assertNotEmpty(data.total_bytes)),
+    total: apiToSmallInt(assertNotEmpty(data.total)),
+    totalBytes: apiToSmallInt(assertNotEmpty(data.total_bytes)),
   };
 }
 
diff --git a/packages/tendermint-rpc/src/tendermint35/encodings.spec.ts b/packages/tendermint-rpc/src/tendermint35/encodings.spec.ts
index afea0600d3..b4921d3b73 100644
--- a/packages/tendermint-rpc/src/tendermint35/encodings.spec.ts
+++ b/packages/tendermint-rpc/src/tendermint35/encodings.spec.ts
@@ -1,6 +1,13 @@
 import { ReadonlyDate } from "readonly-date";
 
-import { encodeBlockId, encodeBytes, encodeInt, encodeString, encodeTime, encodeVersion } from "./encodings";
+import {
+  encodeBlockId,
+  encodeBytes,
+  encodeString,
+  encodeTime,
+  encodeUvarint,
+  encodeVersion,
+} from "./encodings";
 
 describe("encodings", () => {
   describe("encodeString", () => {
@@ -13,14 +20,14 @@ describe("encodings", () => {
     });
   });
 
-  describe("encodeInt", () => {
+  describe("encodeUvarint", () => {
     it("works", () => {
-      expect(encodeInt(0)).toEqual(Uint8Array.from([0]));
-      expect(encodeInt(1)).toEqual(Uint8Array.from([1]));
-      expect(encodeInt(127)).toEqual(Uint8Array.from([127]));
-      expect(encodeInt(128)).toEqual(Uint8Array.from([128, 1]));
-      expect(encodeInt(255)).toEqual(Uint8Array.from([255, 1]));
-      expect(encodeInt(256)).toEqual(Uint8Array.from([128, 2]));
+      expect(encodeUvarint(0)).toEqual(Uint8Array.from([0]));
+      expect(encodeUvarint(1)).toEqual(Uint8Array.from([1]));
+      expect(encodeUvarint(127)).toEqual(Uint8Array.from([127]));
+      expect(encodeUvarint(128)).toEqual(Uint8Array.from([128, 1]));
+      expect(encodeUvarint(255)).toEqual(Uint8Array.from([255, 1]));
+      expect(encodeUvarint(256)).toEqual(Uint8Array.from([128, 2]));
     });
   });
 
diff --git a/packages/tendermint-rpc/src/tendermint35/encodings.ts b/packages/tendermint-rpc/src/tendermint35/encodings.ts
index ec5b072775..037b506898 100644
--- a/packages/tendermint-rpc/src/tendermint35/encodings.ts
+++ b/packages/tendermint-rpc/src/tendermint35/encodings.ts
@@ -1,5 +1,4 @@
 import { toUtf8 } from "@cosmjs/encoding";
-import { Int53 } from "@cosmjs/math";
 
 import { ReadonlyDateWithNanoseconds } from "../dates";
 import { BlockId, Version } from "./responses";
@@ -140,17 +139,6 @@ export function dictionaryToStringMap(obj: Record<string, unknown>): Map<string,
   return out;
 }
 
-export class Integer {
-  public static parse(input: string | number): number {
-    const asInt = typeof input === "number" ? new Int53(input) : Int53.fromString(input);
-    return asInt.toNumber();
-  }
-
-  public static encode(num: number): string {
-    return new Int53(num).toString();
-  }
-}
-
 // Encodings needed for hashing block headers
 // Several of these functions are inspired by https://github.com/nomic-io/js-tendermint/blob/tendermint-0.30/src/
 
@@ -161,18 +149,21 @@ export function encodeString(s: string): Uint8Array {
 }
 
 // See https://github.com/tendermint/go-amino/blob/v0.15.0/encoder.go#L79-L87
-export function encodeInt(n: number): Uint8Array {
-  // eslint-disable-next-line no-bitwise
-  return n >= 0x80 ? Uint8Array.from([(n & 0xff) | 0x80, ...encodeInt(n >> 7)]) : Uint8Array.from([n & 0xff]);
+export function encodeUvarint(n: number): Uint8Array {
+  return n >= 0x80
+    ? // eslint-disable-next-line no-bitwise
+      Uint8Array.from([(n & 0xff) | 0x80, ...encodeUvarint(n >> 7)])
+    : // eslint-disable-next-line no-bitwise
+      Uint8Array.from([n & 0xff]);
 }
 
 // See https://github.com/tendermint/go-amino/blob/v0.15.0/encoder.go#L134-L178
 export function encodeTime(time: ReadonlyDateWithNanoseconds): Uint8Array {
   const milliseconds = time.getTime();
   const seconds = Math.floor(milliseconds / 1000);
-  const secondsArray = seconds ? [0x08, ...encodeInt(seconds)] : new Uint8Array();
+  const secondsArray = seconds ? [0x08, ...encodeUvarint(seconds)] : new Uint8Array();
   const nanoseconds = (time.nanoseconds || 0) + (milliseconds % 1000) * 1e6;
-  const nanosecondsArray = nanoseconds ? [0x10, ...encodeInt(nanoseconds)] : new Uint8Array();
+  const nanosecondsArray = nanoseconds ? [0x10, ...encodeUvarint(nanoseconds)] : new Uint8Array();
   return Uint8Array.from([...secondsArray, ...nanosecondsArray]);
 }
 
@@ -184,8 +175,10 @@ export function encodeBytes(bytes: Uint8Array): Uint8Array {
 }
 
 export function encodeVersion(version: Version): Uint8Array {
-  const blockArray = version.block ? Uint8Array.from([0x08, ...encodeInt(version.block)]) : new Uint8Array();
-  const appArray = version.app ? Uint8Array.from([0x10, ...encodeInt(version.app)]) : new Uint8Array();
+  const blockArray = version.block
+    ? Uint8Array.from([0x08, ...encodeUvarint(version.block)])
+    : new Uint8Array();
+  const appArray = version.app ? Uint8Array.from([0x10, ...encodeUvarint(version.app)]) : new Uint8Array();
   return Uint8Array.from([...blockArray, ...appArray]);
 }
 
diff --git a/packages/tendermint-rpc/src/tendermint35/hasher.ts b/packages/tendermint-rpc/src/tendermint35/hasher.ts
index 65ba6627be..a02d2f814f 100644
--- a/packages/tendermint-rpc/src/tendermint35/hasher.ts
+++ b/packages/tendermint-rpc/src/tendermint35/hasher.ts
@@ -1,6 +1,13 @@
 import { Sha256, sha256 } from "@cosmjs/crypto";
 
-import { encodeBlockId, encodeBytes, encodeInt, encodeString, encodeTime, encodeVersion } from "./encodings";
+import {
+  encodeBlockId,
+  encodeBytes,
+  encodeString,
+  encodeTime,
+  encodeUvarint,
+  encodeVersion,
+} from "./encodings";
 import { Header } from "./responses";
 
 // hash is sha256
@@ -55,7 +62,7 @@ export function hashBlock(header: Header): Uint8Array {
   const encodedFields: readonly Uint8Array[] = [
     encodeVersion(header.version),
     encodeString(header.chainId),
-    encodeInt(header.height),
+    encodeUvarint(header.height),
     encodeTime(header.time),
     encodeBlockId(header.lastBlockId),
 
diff --git a/packages/tendermint-rpc/src/tendermint35/responses.ts b/packages/tendermint-rpc/src/tendermint35/responses.ts
index f03cabcac8..7440d8d927 100644
--- a/packages/tendermint-rpc/src/tendermint35/responses.ts
+++ b/packages/tendermint-rpc/src/tendermint35/responses.ts
@@ -357,13 +357,13 @@ export interface SyncInfo {
 export interface Validator {
   readonly address: Uint8Array;
   readonly pubkey?: ValidatorPubkey;
-  readonly votingPower: number;
+  readonly votingPower: bigint;
   readonly proposerPriority?: number;
 }
 
 export interface ValidatorUpdate {
   readonly pubkey: ValidatorPubkey;
-  readonly votingPower: number;
+  readonly votingPower: bigint;
 }
 
 export interface ConsensusParams {