diff --git a/components/script/dom/domexception.rs b/components/script/dom/domexception.rs
index 19751284bcf..e63cbedafbc 100644
--- a/components/script/dom/domexception.rs
+++ b/components/script/dom/domexception.rs
@@ -104,4 +104,9 @@ impl DOMExceptionMethods for DOMException {
 
         message.to_owned()
     }
+
+    // https://people.mozilla.org/~jorendorff/es6-draft.html#sec-error.prototype.tostring
+    fn Stringifier(&self) -> String {
+        format!("{}: {}", self.Name(), self.Message())
+    }
 }
diff --git a/components/script/dom/webidls/DOMException.webidl b/components/script/dom/webidls/DOMException.webidl
index 7c09054598c..0dfb7149e93 100644
--- a/components/script/dom/webidls/DOMException.webidl
+++ b/components/script/dom/webidls/DOMException.webidl
@@ -44,4 +44,6 @@ interface DOMException {
 
   // A custom message set by the thrower.
   readonly attribute DOMString message;
+
+  stringifier;
 };