diff --git a/mnet/xmlrpc/client.php b/mnet/xmlrpc/client.php
index 02a7cdc65be..39078d25be7 100644
--- a/mnet/xmlrpc/client.php
+++ b/mnet/xmlrpc/client.php
@@ -295,7 +295,8 @@ class mnet_xmlrpc_client {
 
         // ok, it's signed, but is it signed with the right certificate ?
         // do this *after* we check for an out of date key
-        if (!openssl_verify($this->xmlrpcresponse, base64_decode($sig_parser->signature), $mnet_peer->public_key)) {
+        $verified = openssl_verify($this->xmlrpcresponse, base64_decode($sig_parser->signature), $mnet_peer->public_key);
+        if ($verified != 1) {
             $this->error[] = 'Invalid signature';
         }