diff --git a/node_modules/c9/urls.js b/node_modules/c9/urls.js
index 61390bd4..ec134340 100644
--- a/node_modules/c9/urls.js
+++ b/node_modules/c9/urls.js
@@ -39,6 +39,7 @@ plugin.getBaseUrl = function(req, sourceBaseUrlPattern, targetBaseUrlPattern) {
     var sourceHostMatcher = sourceBaseUrlPattern
         .replace(/^https?:\/\//, "")
         .replace(/\/.*/, "")
+        .replace(/\./, "\\.")
         .replace("$DOMAIN", "([^/]+)");
     var hostMatch = sourceHost.match(sourceHostMatcher);
     var targetHost;