diff --git a/.changelog/unreleased/improvements/2016-blocksync-avoid-double-calling-block-from-proto.md b/.changelog/unreleased/improvements/2016-blocksync-avoid-double-calling-block-from-proto.md
new file mode 100644
index 00000000000..7251221be18
--- /dev/null
+++ b/.changelog/unreleased/improvements/2016-blocksync-avoid-double-calling-block-from-proto.md
@@ -0,0 +1,2 @@
+- `[blocksync]` Avoid double-calling `types.BlockFromProto` for performance
+  reasons ([\#2016](https://github.com/cometbft/cometbft/pull/2016))
diff --git a/.github/mergify.yml b/.github/mergify.yml
index 270c06fbb2c..5d98052284c 100644
--- a/.github/mergify.yml
+++ b/.github/mergify.yml
@@ -1,13 +1,19 @@
+defaults:
+  actions:
+    backport:
+      assignees:
+        - "{{ author }}"
+
 queue_rules:
   - name: default
     conditions:
-      - base=main
-      - label=S:automerge
+      - "#approved-reviews-by>=1"
 
 pull_request_rules:
   - name: Automerge to main
     conditions:
-      - base=main
+      - "#approved-reviews-by>=1"
+      - base=osmo/v0.37.4
       - label=S:automerge
     actions:
       queue:
@@ -15,13 +21,12 @@ pull_request_rules:
         name: default
         commit_message_template: |
           {{ title }} (#{{ number }})
-
           {{ body }}
-  - name: backport patches to v0.34.x branch
+  - name: backport patches to v23 branch
     conditions:
-      - base=main
-      - label=S:backport-to-v0.34.x
+      - base=osmo/v0.37.4
+      - label=S:backport/v23
     actions:
       backport:
         branches:
-          - v0.34.x
+          - osmo-v23/v0.37.4
diff --git a/blocksync/msgs.go b/blocksync/msgs.go
index 447748ecb92..74f9b783bbf 100644
--- a/blocksync/msgs.go
+++ b/blocksync/msgs.go
@@ -31,10 +31,9 @@ func ValidateMsg(pb proto.Message) error {
 			return errors.New("negative Height")
 		}
 	case *bcproto.BlockResponse:
-		_, err := types.BlockFromProto(msg.Block)
-		if err != nil {
-			return err
-		}
+		// Avoid double-calling `types.BlockFromProto` for performance reasons.
+		// See https://github.com/cometbft/cometbft/issues/1964
+		return nil
 	case *bcproto.NoBlockResponse:
 		if msg.Height < 0 {
 			return errors.New("negative Height")
diff --git a/blocksync/reactor.go b/blocksync/reactor.go
index c05d7e2f3f8..629fbbedc40 100644
--- a/blocksync/reactor.go
+++ b/blocksync/reactor.go
@@ -230,7 +230,8 @@ func (bcR *Reactor) ReceiveEnvelope(e p2p.Envelope) {
 	case *bcproto.BlockResponse:
 		bi, err := types.BlockFromProto(msg.Block)
 		if err != nil {
-			bcR.Logger.Error("Block content is invalid", "err", err)
+			bcR.Logger.Error("Peer sent us invalid block", "peer", e.Src, "msg", e.Message, "err", err)
+			bcR.Switch.StopPeerForError(e.Src, err)
 			return
 		}
 		bcR.pool.AddBlock(e.Src.ID(), bi, msg.Block.Size())
@@ -419,7 +420,7 @@ FOR_LOOP:
 
 			// TODO: same thing for app - but we would need a way to
 			// get the hash without persisting the state
-			state, _, err = bcR.blockExec.ApplyBlock(state, firstID, first)
+			state, err = bcR.blockExec.ApplyVerifiedBlock(state, firstID, first)
 			if err != nil {
 				// TODO This is bad, are we zombie?
 				panic(fmt.Sprintf("Failed to process committed block (%d:%X): %v", first.Height, first.Hash(), err))
diff --git a/mempool/nop_mempool.go b/mempool/nop_mempool.go
index 28ce974703a..0e5b451e8dc 100644
--- a/mempool/nop_mempool.go
+++ b/mempool/nop_mempool.go
@@ -109,7 +109,4 @@ func (*NopMempoolReactor) ReceiveEnvelope(p2p.Envelope) {}
 // SetSwitch does nothing.
 func (*NopMempoolReactor) SetSwitch(*p2p.Switch) {}
 
-// AppHashErrorsCh always returns nil.
-func (r *NopMempoolReactor) AppHashErrorsCh() chan p2p.AppHashError {
-	return nil
-}
+func (*NopMempoolReactor) AppHashErrorsCh() chan p2p.AppHashError { return nil }
diff --git a/state/execution.go b/state/execution.go
index 4d312a99ea7..6a460d4bfe9 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -179,6 +179,14 @@ func (blockExec *BlockExecutor) ValidateBlock(state State, block *types.Block) e
 	return blockExec.evpool.CheckEvidence(block.Evidence.Evidence)
 }
 
+// ApplyVerifiedBlock does the same as `ApplyBlock`, but skips verification.
+func (blockExec *BlockExecutor) ApplyVerifiedBlock(
+	state State, blockID types.BlockID, block *types.Block,
+) (State, error) {
+	newState, _, err := blockExec.applyBlock(state, blockID, block)
+	return newState, err
+}
+
 // ApplyBlock validates the block against the state, executes it against the app,
 // fires the relevant events, commits the app, and saves the new state and responses.
 // It returns the new state and the block height to retain (pruning older blocks).
@@ -193,6 +201,10 @@ func (blockExec *BlockExecutor) ApplyBlock(
 		return state, 0, ErrInvalidBlock(err)
 	}
 
+	return blockExec.applyBlock(state, blockID, block)
+}
+
+func (blockExec *BlockExecutor) applyBlock(state State, blockID types.BlockID, block *types.Block) (State, int64, error) {
 	startTime := time.Now().UnixNano()
 	abciResponses, err := execBlockOnProxyApp(
 		blockExec.logger, blockExec.proxyApp, block, blockExec.store, state.InitialHeight,