diff --git a/client/x/evmengine/keeper/keeper.go b/client/x/evmengine/keeper/keeper.go
index f3b3086c..41e265a3 100644
--- a/client/x/evmengine/keeper/keeper.go
+++ b/client/x/evmengine/keeper/keeper.go
@@ -172,6 +172,12 @@ func (k *Keeper) parseAndVerifyProposedPayload(ctx context.Context, msg *types.M
 //
 // Note that the validator set can change, so this is an optimistic check.
 func (k *Keeper) isNextProposer(ctx context.Context, currentProposer []byte, currentHeight int64) (bool, error) {
+	// PostFinalize can be called during block replay (performed in newCometNode),
+	// but cmtAPI is set only after newCometNode completes (see app.SetCometAPI), so a nil check is necessary.
+	if k.cmtAPI == nil {
+		return false, nil
+	}
+
 	valset, ok, err := k.cmtAPI.Validators(ctx, currentHeight)
 	if err != nil {
 		return false, err