diff --git a/src/shared/utils/ReactElementSymbol.js b/src/shared/utils/ReactElementSymbol.js
index 7547e2471b..9d59d505e7 100644
--- a/src/shared/utils/ReactElementSymbol.js
+++ b/src/shared/utils/ReactElementSymbol.js
@@ -7,6 +7,7 @@
  * of patent rights can be found in the PATENTS file in the same directory.
  *
  * @providesModule ReactElementSymbol
+ * @flow
  */
 
 'use strict';