diff --git a/src/Ui/UiWebsocket.py b/src/Ui/UiWebsocket.py
index 9efc095a..ae074aed 100644
--- a/src/Ui/UiWebsocket.py
+++ b/src/Ui/UiWebsocket.py
@@ -473,7 +473,8 @@ class UiWebsocket(object):
             s = time.time()
         rows = []
         try:
-            assert query.strip().upper().startswith("SELECT"), "Only SELECT query supported"
+            if not query.strip().upper().startswith("SELECT"):
+                raise Exception("Only SELECT query supported")
             res = self.site.storage.query(query, params)
         except Exception, err:  # Response the error to client
             return self.response(to, {"error": str(err)})