diff --git a/src/cmd/godoc/godoc.go b/src/cmd/godoc/godoc.go
index 7cf5a851978..dd5278f8e74 100644
--- a/src/cmd/godoc/godoc.go
+++ b/src/cmd/godoc/godoc.go
@@ -859,6 +859,7 @@ func isTextFile(path string) bool {
 	if err != nil {
 		return false
 	}
+	defer f.Close();
 
 	var buf [1024]byte;
 	n, err := f.Read(&buf);