diff --git a/src/transform.js b/src/transform.js
index ecbd06e4b8..ad08fe9926 100644
--- a/src/transform.js
+++ b/src/transform.js
@@ -307,14 +307,14 @@ transform.lookup = function (projection) {
   code = parts[1];
 
   return $.ajax({
-    url: 'https://epsg.io/?q=' + code + '&format=json'
+    url: 'https://epsg.io/' + encodeURIComponent(code) + '.proj4'
   }).done(function (data) {
     var result = (data.results || [])[0];
-    if (!result || !result.proj4) {
+    if (!result) {
       return defer.reject(data).promise();
     }
 
-    proj4.defs(projection, result.proj4);
+    proj4.defs(projection, result);
     return $.when(proj4.defs[projection]);
   });
 };
diff --git a/tests/cases/transform.js b/tests/cases/transform.js
index bc43e03113..3f5813c9da 100644
--- a/tests/cases/transform.js
+++ b/tests/cases/transform.js
@@ -124,7 +124,7 @@ describe('geo.transform', function () {
       geo.transform.lookup('EPSG:5000').then(spy);
 
       request = server.requests[0];
-      expect(request.url).toMatch(/\?q=5000/);
+      expect(request.url).toMatch(/5000\.proj4/);
       request.respond(200, {'Content-Type': 'application/json'}, JSON.stringify({
         status: 'ok',
         number_result: 1,