diff --git a/modules/forum.module b/modules/forum.module
index d6b324d29155ec3f5f2ecf94695417d26e7a76af..dd409b9cdc901181728bc4f7193e6415196ce0e2 100644
--- a/modules/forum.module
+++ b/modules/forum.module
@@ -238,7 +238,7 @@ function _forum_parent_select($tid, $title, $child_type) {
     $parent = 0;
   }
 
-  $children = taxonomy_get_tree(_forum_get_vid, $tid);
+  $children = taxonomy_get_tree(_forum_get_vid(), $tid);
 
   // A term can't be the child of itself, nor of its children.
   foreach ($children as $child) {
diff --git a/modules/forum/forum.module b/modules/forum/forum.module
index d6b324d29155ec3f5f2ecf94695417d26e7a76af..dd409b9cdc901181728bc4f7193e6415196ce0e2 100644
--- a/modules/forum/forum.module
+++ b/modules/forum/forum.module
@@ -238,7 +238,7 @@ function _forum_parent_select($tid, $title, $child_type) {
     $parent = 0;
   }
 
-  $children = taxonomy_get_tree(_forum_get_vid, $tid);
+  $children = taxonomy_get_tree(_forum_get_vid(), $tid);
 
   // A term can't be the child of itself, nor of its children.
   foreach ($children as $child) {