diff --git a/atom/browser/lib/guest-window-manager.coffee b/atom/browser/lib/guest-window-manager.coffee
index 5ff59f5ad2fb..3b331260b1aa 100644
--- a/atom/browser/lib/guest-window-manager.coffee
+++ b/atom/browser/lib/guest-window-manager.coffee
@@ -34,7 +34,7 @@ createGuest = (embedder, url, frameName, options) ->
 
   ipc.on 'ATOM_SHELL_GUEST_WINDOW_MANAGER_WINDOW_OPENER_POSTMESSAGE', (event, method, args...) ->
     if embedder.getUrl().indexOf(args[1]) is 0 or args[1] is '*'
-      embedder.send 'ATOM_SHELL_GUEST_WINDOW_MANAGER_WINDOW_POSTMESSAGE', args[0], args[1];
+      embedder.send 'ATOM_SHELL_GUEST_WINDOW_MANAGER_WINDOW_POSTMESSAGE', args[0], args[1]
 
   guest.id
 
diff --git a/atom/renderer/lib/override.coffee b/atom/renderer/lib/override.coffee
index e158497e6ae1..eba0e9c98253 100644
--- a/atom/renderer/lib/override.coffee
+++ b/atom/renderer/lib/override.coffee
@@ -21,7 +21,7 @@ class FakeWindow
     ipc.send 'ATOM_SHELL_GUEST_WINDOW_MANAGER_WINDOW_METHOD', @guestId, 'blur'
 
   postMessage: (args...) ->
-    ipc.send 'ATOM_SHELL_GUEST_WINDOW_MANAGER_WINDOW_POSTMESSAGE', @guestId, 'postMessage', args[0], args[1];
+    ipc.send 'ATOM_SHELL_GUEST_WINDOW_MANAGER_WINDOW_POSTMESSAGE', @guestId, 'postMessage', args[0], args[1]
 
   eval: (args...) ->
     ipc.send 'ATOM_SHELL_GUEST_WINDOW_MANAGER_WEB_CONTENTS_METHOD', @guestId, 'executeJavaScript', args...