diff --git a/src/hb-serialize.hh b/src/hb-serialize.hh
index 87aafe0e2..e05fa15d0 100644
--- a/src/hb-serialize.hh
+++ b/src/hb-serialize.hh
@@ -161,7 +161,7 @@ struct hb_serialize_context_t
                       hb_serialize_error_t err_type = HB_SERIALIZE_ERROR_OTHER)
   {
     return successful ()
-        && (success || err (err_type));
+        && (success || !err (err_type));
   }
 
   template <typename T1, typename T2>