diff --git a/mod/forum/lib.php b/mod/forum/lib.php
index 0b1dd0f58c5..d3ef01894dd 100644
--- a/mod/forum/lib.php
+++ b/mod/forum/lib.php
@@ -2320,7 +2320,12 @@ function forum_file_area_name($post) {
 }
 
 function forum_file_area($post) {
-    return make_upload_directory( forum_file_area_name($post) );
+    $path = forum_file_area_name($post);
+    if ($path) {
+        return make_upload_directory($path);
+    } else {
+        return false;
+    }
 }
 
 function forum_delete_old_attachments($post, $exception="") {