diff --git a/node_modules/c9/urls.js b/node_modules/c9/urls.js
index 0ac974d0..e358793e 100644
--- a/node_modules/c9/urls.js
+++ b/node_modules/c9/urls.js
@@ -30,7 +30,7 @@ function main(options, imports, register) {
  * @param {String} [targetBaseUrlPattern] The target URL pattern, e.g. https://$DOMAIN
  */
 plugin.getBaseUrl = function(req, sourceBaseUrlPattern, targetBaseUrlPattern) {
-    var sourceHost = req.host || req;
+    var sourceHost = req.headers && req.headers.host || req.host || req;
     var sourceHostMatcher = sourceBaseUrlPattern
         .replace(/^https?:\/\//, "")
         .replace(/\/.*/, "")
@@ -39,10 +39,12 @@ plugin.getBaseUrl = function(req, sourceBaseUrlPattern, targetBaseUrlPattern) {
     if (!hostMatch) {
         errorLogger.log(new Error("Could not construct URL: request host "
             + sourceHost + " should match " + sourceBaseUrlPattern));
-        return replaceDomain(targetBaseUrlPattern || sourceBaseUrlPattern, "c9.io");
+        return replaceDomain(targetBaseUrlPattern || sourceBaseUrlPattern, "c9.io")
+            .replace(/\/$/, "");
     }
     
-    return replaceDomain(targetBaseUrlPattern || sourceBaseUrlPattern, hostMatch[1]);
+    return replaceDomain(targetBaseUrlPattern || sourceBaseUrlPattern, hostMatch[1])
+        .replace(/\/$/, "");;
 };
 
 plugin.replaceDomains = function(settings, domains) {