diff --git a/custom-idl/webkit.idl b/custom-idl/webkit.idl
deleted file mode 100644
index 42bb9f300..000000000
--- a/custom-idl/webkit.idl
+++ /dev/null
@@ -1,39 +0,0 @@
-partial interface Element {
-  // https://github.com/WebKit/WebKit/blob/cdb06d0c41ff04eff8f4c65d1c92c8672b4903a6/Source/WebCore/dom/Element.idl#L74
-  attribute EventHandler onbeforeload;
-  attribute EventHandler onfocusin;
-  attribute EventHandler onfocusout;
-  attribute EventHandler ongesturechange;
-  attribute EventHandler ongestureend;
-  attribute EventHandler ongesturestart;
-};
-
-partial interface mixin GlobalEventHandlers {
-  // https://github.com/WebKit/WebKit/blob/cdb06d0c41ff04eff8f4c65d1c92c8672b4903a6/Source/WebCore/dom/GlobalEventHandlers.idl#L114
-  attribute EventHandler onwebkitmouseforcechanged;
-  attribute EventHandler onwebkitmouseforcedown;
-  attribute EventHandler onwebkitmouseforcewillbegin;
-  attribute EventHandler onwebkitmouseforceup;
-};
-
-partial interface HTMLBodyElement {
-  // https://github.com/WebKit/WebKit/blob/cdb06d0c41ff04eff8f4c65d1c92c8672b4903a6/Source/WebCore/html/HTMLBodyElement.idl#L31
-  attribute EventHandler onblur;
-  attribute EventHandler onerror;
-  attribute EventHandler onfocus;
-  attribute EventHandler onfocusin;
-  attribute EventHandler onfocusout;
-  attribute EventHandler onload;
-  attribute EventHandler onresize;
-  attribute EventHandler onscroll;
-  attribute EventHandler onselectionchange;
-  attribute EventHandler onwebkitmouseforcechanged;
-  attribute EventHandler onwebkitmouseforcedown;
-  attribute EventHandler onwebkitmouseforceup;
-  attribute EventHandler onwebkitmouseforcewillbegin;
-};
-
-partial interface HTMLElement {
-  // https://github.com/WebKit/WebKit/blob/c397d717fcd82a8daff69dccb1354a5f94ca6f9a/Source/WebCore/html/HTMLElement.idl#L57
-  [CEReactions] attribute DOMString webkitdropzone;
-};