diff --git a/components/script/dom/eventtarget.rs b/components/script/dom/eventtarget.rs
index b65fcc6baf1..21225da300b 100644
--- a/components/script/dom/eventtarget.rs
+++ b/components/script/dom/eventtarget.rs
@@ -495,7 +495,7 @@ impl EventTarget {
         // Step 3.9
 
         let url_serialized = CString::new(handler.url.to_string()).unwrap();
-        let name = CString::new(&**ty).unwrap();
+        let name = CString::new(format!("on{}", &**ty)).unwrap();
 
         // Step 3.9, subsection ParameterList
         static mut ARG_NAMES: [*const c_char; 1] = [b"event\0" as *const u8 as *const c_char];
diff --git a/tests/wpt/metadata-layout-2020/html/webappapis/scripting/events/event-handler-sourcetext.html.ini b/tests/wpt/metadata-layout-2020/html/webappapis/scripting/events/event-handler-sourcetext.html.ini
deleted file mode 100644
index eb4c9a05f2d..00000000000
--- a/tests/wpt/metadata-layout-2020/html/webappapis/scripting/events/event-handler-sourcetext.html.ini
+++ /dev/null
@@ -1,16 +0,0 @@
-[event-handler-sourcetext.html]
-  [error event handler on disconnected body]
-    expected: FAIL
-
-  [error event handler not on body]
-    expected: FAIL
-
-  [error event handler on connected body, reflected to Window]
-    expected: FAIL
-
-  [error event handler on disconnected frameset]
-    expected: FAIL
-
-  [non-error event handler]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/webappapis/scripting/events/event-handler-sourcetext.html.ini b/tests/wpt/metadata/html/webappapis/scripting/events/event-handler-sourcetext.html.ini
deleted file mode 100644
index eb4c9a05f2d..00000000000
--- a/tests/wpt/metadata/html/webappapis/scripting/events/event-handler-sourcetext.html.ini
+++ /dev/null
@@ -1,16 +0,0 @@
-[event-handler-sourcetext.html]
-  [error event handler on disconnected body]
-    expected: FAIL
-
-  [error event handler not on body]
-    expected: FAIL
-
-  [error event handler on connected body, reflected to Window]
-    expected: FAIL
-
-  [error event handler on disconnected frameset]
-    expected: FAIL
-
-  [non-error event handler]
-    expected: FAIL
-