diff --git a/types/block.go b/types/block.go
index ab79d59ff..00a28d1f8 100644
--- a/types/block.go
+++ b/types/block.go
@@ -772,10 +772,8 @@ func (ecs ExtendedCommitSig) ValidateBasic() error {
 // EnsureExtensions validates that a vote extensions signature is present for
 // this ExtendedCommitSig.
 func (ecs ExtendedCommitSig) EnsureExtension() error {
-	if ecs.BlockIDFlag == BlockIDFlagCommit {
-		if len(ecs.ExtensionSignature) == 0 {
-			return errors.New("vote extension signature is missing")
-		}
+	if ecs.BlockIDFlag == BlockIDFlagCommit && len(ecs.ExtensionSignature) == 0 {
+		return errors.New("vote extension signature is missing")
 	}
 	return nil
 }