diff --git a/includes/actions.inc b/includes/actions.inc
index f997535..cf1b23f 100644
--- a/includes/actions.inc
+++ b/includes/actions.inc
@@ -128,7 +128,9 @@ function actions_do($action_ids, &$object, $context = NULL, $a1 = NULL, $a2 = NU
       }
       // Singleton action; $action_id is the function name.
       else {
-        $result[$action_id] = $action_id($object, $context, $a1, $a2);
+        if (function_exists($action_id)) {
+          $result[$action_id] = $action_id($object, $context, $a1, $a2);
+        }
       }
     }
   }
@@ -148,7 +150,9 @@ function actions_do($action_ids, &$object, $context = NULL, $a1 = NULL, $a2 = NU
     }
     // Singleton action; $action_ids is the function name.
     else {
-      $result[$action_ids] = $action_ids($object, $context, $a1, $a2);
+      if (function_exists($action_ids)) {
+        $result[$action_ids] = $action_ids($object, $context, $a1, $a2);
+      }
     }
   }
   $stack--;