diff --git a/filters/all.js b/filters/all.js
index 6dbce5ce5..3e5c6f035 100644
--- a/filters/all.js
+++ b/filters/all.js
@@ -101,7 +101,7 @@ function isDefined(obj) {
 filter.isDefined = isDefined;
 
 function isProtocol(api, protocol){
-  return JSON.stringify(api.json()).includes('"protocol":"' + protocol + '"');
+  return api.constructor.stringify(api).includes('"protocol":"' + protocol + '"');
 };
 filter.isProtocol = isProtocol;
 
diff --git a/package.json b/package.json
index e87fbc481..2e2823505 100644
--- a/package.json
+++ b/package.json
@@ -33,7 +33,7 @@
     "@asyncapi/generator-filters": "^2.1.0",
     "@asyncapi/generator-hooks": "^0.1.0",
     "fs-extra": "^9.0.0",
-    "lodash": "^4.17.15",
+    "lodash": "^4.17.21",
     "replace-in-file": "^6.1.0",
     "tmp": "^0.2.1"
   },
@@ -127,7 +127,7 @@
         "required": false
       }
     },
-    "generator": ">=0.50.0 <2.0.0",
+    "generator": ">=1.8.27 <2.0.0",
     "filters": [
       "@asyncapi/generator-filters"
     ],