diff --git a/lib/components/ModalPortal.js b/lib/components/ModalPortal.js
index 78d846b4..3372f3c9 100644
--- a/lib/components/ModalPortal.js
+++ b/lib/components/ModalPortal.js
@@ -9,12 +9,12 @@ var CLASS_NAMES = {
   overlay: {
     base: 'ReactModal__Overlay',
     afterOpen: 'ReactModal__Overlay--after-open',
-    beforeClose: 'ReactModal__Overlay--before-close',
+    beforeClose: 'ReactModal__Overlay--before-close'
   },
   content: {
     base: 'ReactModal__Content',
     afterOpen: 'ReactModal__Content--after-open',
-    beforeClose: 'ReactModal__Content--before-close',
+    beforeClose: 'ReactModal__Content--before-close'
   }
 };