diff --git a/src/pkg/path/filepath/path_plan9.go b/src/pkg/path/filepath/path_plan9.go
index cf028a75c5..59a5812dd0 100644
--- a/src/pkg/path/filepath/path_plan9.go
+++ b/src/pkg/path/filepath/path_plan9.go
@@ -12,7 +12,7 @@ func IsAbs(path string) bool {
 }
 
 // VolumeName returns the leading volume name on Windows.
-// It returns "" elsewhere
+// It returns "" elsewhere.
 func VolumeName(path string) string {
 	return ""
 }