diff --git a/src/runtime/pprof/label.go b/src/runtime/pprof/label.go
index 35647ee3ce1f21..20f9cdbae6fe0b 100644
--- a/src/runtime/pprof/label.go
+++ b/src/runtime/pprof/label.go
@@ -54,6 +54,8 @@ func WithLabels(ctx context.Context, labels LabelSet) context.Context {
 // Labels takes an even number of strings representing key-value pairs
 // and makes a LabelSet containing them.
 // A label overwrites a prior label with the same key.
+// Currently only CPU profile utilizes labels information.
+// See https://golang.org/issue/23458 for details.
 func Labels(args ...string) LabelSet {
 	if len(args)%2 != 0 {
 		panic("uneven number of arguments to pprof.Labels")