diff --git a/js/qz-tray.js b/js/qz-tray.js
index ba51b21d..3dcfb884 100644
--- a/js/qz-tray.js
+++ b/js/qz-tray.js
@@ -963,7 +963,8 @@ var qz = (function() {
             /** Check if QZ version supports chosen algorithm */
             algorithm: function(quiet) {
                 //if not connected yet we will assume compatibility exists for the time being
-                if (_qz.tools.isActive()) {
+                //check semver to guard race condition for pending connections
+                if (_qz.tools.isActive() && _qz.websocket.connection.semver) {
                     if (_qz.tools.isVersion(2, 0)) {
                         if (!quiet) {
                             _qz.log.warn("Connected to an older version of QZ, alternate signature algorithms are not supported");