diff --git a/inputfiles/addedTypes.jsonc b/inputfiles/addedTypes.jsonc
index 98f5d020c..103a7e666 100644
--- a/inputfiles/addedTypes.jsonc
+++ b/inputfiles/addedTypes.jsonc
@@ -234,19 +234,6 @@
                 "extends": "DOMRect",
                 "noInterfaceObject": true
             },
-            "EventListenerObject": {
-                "name": "EventListenerObject",
-                "noInterfaceObject": true,
-                "methods": {
-                    "method": {
-                        "handleEvent": {
-                            "overrideSignatures": [
-                                "handleEvent(object: Event): void"
-                            ]
-                        }
-                    }
-                }
-            },
             "Document": {
                 "methods": {
                     "method": {
diff --git a/inputfiles/patches/dom.kdl b/inputfiles/patches/dom.kdl
index 01bb7d1c3..146a24389 100644
--- a/inputfiles/patches/dom.kdl
+++ b/inputfiles/patches/dom.kdl
@@ -1,15 +1,21 @@
 // Keeping EventListener and EventListenerObject isn't the most elegant way to handle the event listeners, but we need to keep the EventListener as an extendable interface for libraries like angular.
 interface EventListener noInterfaceObject=#true {
-    method "" returns=void {
-        param evt type=Event
-    }
+  method "" returns=undefined {
+    param evt type=Event
+  }
+}
+
+interface EventListenerObject noInterfaceObject=#true {
+  method handleEvent returns=undefined {
+    param object type=Event
+  }
 }
 
 enum InsertPosition {
-    beforebegin
-    beforeend
-    afterbegin
-    afterend
+  beforebegin
+  beforeend
+  afterbegin
+  afterend
 }
 
 // ChildNode and ParentNode are actually defined as mixins, but because of their names they have historically been used as a sub-interface of Node.