diff --git a/js/id/util.js b/js/id/util.js
index 7c96480be..660f164dd 100644
--- a/js/id/util.js
+++ b/js/id/util.js
@@ -41,7 +41,11 @@ iD.util.stringQs = function(str) {
 };
 
 iD.util.qsString = function(obj, noencode) {
-    function softEncode(s) { return s.replace('&', '%26').replace('=', '%3D'); }
+    function softEncode(s) {
+      // encode everything except special characters used in certain hash parameters:
+      // "/" in map states, ":", ",", {" and "}" in background
+      return encodeURIComponent(s).replace(/(%2F|%3A|%2C|%7B|%7D)/g, decodeURIComponent);
+    }
     return Object.keys(obj).sort().map(function(key) {
         return encodeURIComponent(key) + '=' + (
             noencode ? softEncode(obj[key]) : encodeURIComponent(obj[key]));