diff --git a/types/block.go b/types/block.go
index 4f0e22751..a975e7e7a 100644
--- a/types/block.go
+++ b/types/block.go
@@ -754,7 +754,7 @@ func (ecs ExtendedCommitSig) ForBlock() bool {
 
 // Absent returns true if ExtendedCommitSig is absent.
 func (ecs ExtendedCommitSig) Absent() bool {
-	//TODO What about BlockIDFlagNil?
+	// TODO(sergio): What about BlockIDFlagNil?
 	return ecs.BlockIDFlag == BlockIDFlagAbsent
 }