1 files changed, 4 insertions, 1 deletions
diff --git a/includes/module.inc b/includes/module.inc
index 18c7dfb4c..62c2cbae9 100644
--- a/includes/module.inc
+++ b/includes/module.inc
@@ -238,9 +238,12 @@ function module_invoke_all($hook, $a1 = NULL, $a2 = NULL, $a3 = NULL, $a4 = NULL
   $return = array();
   foreach (module_list() as $module) {
     $result = module_invoke($module, $hook, $a1, $a2, $a3, $a4);
-    if (isset($result)) {
+    if (is_array($result)) {
       $return = array_merge($return, $result);
     }
+    else if (isset($result)) {
+      $return[] = $result;
+    }
   }
 
   return $return;