diff --git a/tensorflow/core/platform/test.h b/tensorflow/core/platform/test.h
index 5ef6777f583..a2cda11c608 100644
--- a/tensorflow/core/platform/test.h
+++ b/tensorflow/core/platform/test.h
@@ -34,6 +34,8 @@ namespace tensorflow {
 namespace testing {
 
 // Return a temporary directory suitable for temporary testing files.
+//
+// Where possible, consider using Env::LocalTempFilename over this function.
 string TmpDir();
 
 // Returns the path to TensorFlow in the directory containing data