diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+- 0.3.4.3.22.2
+    - Fix #67: We didn't use served `swagger.json`
+
 - 0.3.3.3.22.2
     - Update to `swagger-ui-3.22.2`
     - Add `swaggerSchemaUIServer'`
diff --git a/index.html.tmpl b/index.html.tmpl
--- a/index.html.tmpl
+++ b/index.html.tmpl
@@ -47,9 +47,18 @@
     <script src="./swagger-ui-standalone-preset.js"> </script>
     <script>
     window.onload = function() {
+      // servant-swagger-ui addition
+      var ssuDir = "SERVANT_SWAGGER_UI_DIR";
+      var ssuSchema = "SERVANT_SWAGGER_UI_SCHEMA";
+      // more concretely:
+      // replace /swagger-ui/ or /swagger-ui/index.html with /swagger.json
+      // we always have trailing slash!
+      var re = new RegExp("\/" + ssuDir + "/(?:index\\.html)?$","g");
+      var url = window.location.pathname.replace(re, "/" + ssuSchema);
+
       // Begin Swagger UI call region
       const ui = SwaggerUIBundle({
-        url: "https://petstore.swagger.io/v2/swagger.json",
+        url: url,
         dom_id: '#swagger-ui',
         deepLinking: true,
         presets: [
diff --git a/servant-swagger-ui.cabal b/servant-swagger-ui.cabal
--- a/servant-swagger-ui.cabal
+++ b/servant-swagger-ui.cabal
@@ -1,6 +1,6 @@
 cabal-version:      1.12
 name:               servant-swagger-ui
-version:            0.3.3.3.22.2
+version:            0.3.4.3.22.2
 synopsis:           Servant swagger ui
 category:           Web, Servant, Swagger
 description: