correct check for error in subscribe and unsubscribe actions

1 files changed, 1 insertions, 1 deletions

diff --git a/actions/subscribe.php b/actions/subscribe.php
index 4c46806e4..a90d7facd 100644
--- a/actions/subscribe.php
+++ b/actions/subscribe.php
@@ -58,7 +58,7 @@ class SubscribeAction extends Action
 
         $result = subs_subscribe_to($user, $other);
 
-        if($result != true) {
+        if (is_string($result)) {
             $this->clientError($result);
             return;
         }