diff --git a/modules/contextual/contextual.module b/modules/contextual/contextual.module
index f0e6e032c16f29acb3574f9b0c29ec0cf1f4720b..9e4cc2c42c5f2bf247630a0f3a63b97d9627944b 100644
--- a/modules/contextual/contextual.module
+++ b/modules/contextual/contextual.module
@@ -95,7 +95,7 @@ function contextual_preprocess(&$variables, $hook) {
   }
 
   // Determine the primary theme function argument.
-  if (isset($hooks[$hook]['variables'])) {
+  if (!empty($hooks[$hook]['variables'])) {
     $keys = array_keys($hooks[$hook]['variables']);
     $key = $keys[0];
   }