diff --git a/components/script/dom/bindings/error.rs b/components/script/dom/bindings/error.rs
index b0b6ca1f685..dc03b660824 100644
--- a/components/script/dom/bindings/error.rs
+++ b/components/script/dom/bindings/error.rs
@@ -6,7 +6,6 @@
 
 #[cfg(feature = "js_backtrace")]
 use crate::dom::bindings::cell::DomRefCell;
-use crate::dom::bindings::codegen::Bindings::DOMExceptionBinding::DOMExceptionMethods;
 use crate::dom::bindings::codegen::PrototypeList::proto_id_to_name;
 use crate::dom::bindings::conversions::root_from_object;
 use crate::dom::bindings::conversions::{
@@ -221,7 +220,7 @@ impl ErrorInfo {
 
         Some(ErrorInfo {
             filename: "".to_string(),
-            message: exception.Stringifier().into(),
+            message: exception.stringifier().into(),
             lineno: 0,
             column: 0,
         })
diff --git a/components/script/dom/domexception.rs b/components/script/dom/domexception.rs
index 3cfe6092dd1..218771851b6 100644
--- a/components/script/dom/domexception.rs
+++ b/components/script/dom/domexception.rs
@@ -149,6 +149,11 @@ impl DOMException {
             DOMExceptionBinding::Wrap,
         ))
     }
+
+    // not an IDL stringifier, used internally
+    pub fn stringifier(&self) -> DOMString {
+        DOMString::from(format!("{}: {}", self.name, self.message))
+    }
 }
 
 impl DOMExceptionMethods for DOMException {
@@ -169,9 +174,4 @@ impl DOMExceptionMethods for DOMException {
     fn Message(&self) -> DOMString {
         self.message.clone()
     }
-
-    // https://people.mozilla.org/~jorendorff/es6-draft.html#sec-error.prototype.tostring
-    fn Stringifier(&self) -> DOMString {
-        DOMString::from(format!("{}: {}", self.name, self.message))
-    }
 }
diff --git a/components/script/dom/webidls/DOMException.webidl b/components/script/dom/webidls/DOMException.webidl
index 8475238cb9b..d61d30151fa 100644
--- a/components/script/dom/webidls/DOMException.webidl
+++ b/components/script/dom/webidls/DOMException.webidl
@@ -47,6 +47,4 @@ interface DOMException {
 
   // A custom message set by the thrower.
   readonly attribute DOMString message;
-
-  stringifier;
 };
diff --git a/tests/wpt/metadata/WebIDL/ecmascript-binding/es-exceptions/DOMException-custom-bindings.any.js.ini b/tests/wpt/metadata/WebIDL/ecmascript-binding/es-exceptions/DOMException-custom-bindings.any.js.ini
deleted file mode 100644
index 42a98e14b09..00000000000
--- a/tests/wpt/metadata/WebIDL/ecmascript-binding/es-exceptions/DOMException-custom-bindings.any.js.ini
+++ /dev/null
@@ -1,17 +0,0 @@
-[DOMException-custom-bindings.any.worker.html]
-  type: testharness
-  [Inherits its toString() from Error.prototype]
-    expected: FAIL
-
-  [toString() behavior from Error.prototype applies as expected]
-    expected: FAIL
-
-
-[DOMException-custom-bindings.any.html]
-  type: testharness
-  [Inherits its toString() from Error.prototype]
-    expected: FAIL
-
-  [toString() behavior from Error.prototype applies as expected]
-    expected: FAIL
-