diff --git a/packages/protobuf/src/from-binary.ts b/packages/protobuf/src/from-binary.ts
index 1c1267ad9..9d5153e0c 100644
--- a/packages/protobuf/src/from-binary.ts
+++ b/packages/protobuf/src/from-binary.ts
@@ -77,7 +77,7 @@ export function mergeFromBinary<Desc extends DescMessage>(
   target: MessageShape<Desc>,
   bytes: Uint8Array,
   options?: Partial<BinaryReadOptions>,
-): MessageShape<Desc> {
+): void {
   readMessage(
     reflect(messageDesc, target),
     new BinaryReader(bytes),
@@ -85,7 +85,6 @@ export function mergeFromBinary<Desc extends DescMessage>(
     false,
     bytes.byteLength,
   );
-  return target;
 }
 
 /**
diff --git a/packages/protobuf/src/from-json.ts b/packages/protobuf/src/from-json.ts
index 68f662b4c..e1fdb86c1 100644
--- a/packages/protobuf/src/from-json.ts
+++ b/packages/protobuf/src/from-json.ts
@@ -110,8 +110,8 @@ export function mergeFromJsonString<Desc extends DescMessage>(
   target: MessageShape<Desc>,
   json: string,
   options?: Partial<JsonReadOptions>,
-): MessageShape<Desc> {
-  return mergeFromJson(
+): void {
+  mergeFromJson(
     messageDesc,
     target,
     parseJsonString(json, messageDesc.typeName),
@@ -156,7 +156,7 @@ export function mergeFromJson<Desc extends DescMessage>(
   target: MessageShape<Desc>,
   json: JsonValue,
   options?: Partial<JsonReadOptions>,
-): MessageShape<Desc> {
+): void {
   try {
     readMessage(reflect(messageDesc, target), json, makeReadOptions(options));
   } catch (e) {
@@ -168,7 +168,6 @@ export function mergeFromJson<Desc extends DescMessage>(
     }
     throw e;
   }
-  return target;
 }
 
 function readMessage(