diff --git a/README.md b/README.md
index 31ccd938..c0a4e51f 100644
--- a/README.md
+++ b/README.md
@@ -45,23 +45,6 @@ In the browser:
 </script>
 ```
 
-### Advanced Parsing
-
-`parse()` can optionally accept a second parameter, an options object, which can be used to
-modify parsing behavior.
-
-The following options are recognized:
-```JS
-{
-  allowNestedTypedefs: false
-}
-```
-
-And their meanings are as follows:
-
-* `allowNestedTypedefs`: Boolean indicating whether the parser should accept `typedef`s as valid members of `interface`s.
-This is non-standard syntax and therefore the default is `false`.
-
 ### Errors
 
 When there is a syntax error in the WebIDL, it throws an exception object with the following
diff --git a/lib/webidl2.js b/lib/webidl2.js
index f2f9c547..635643e4 100644
--- a/lib/webidl2.js
+++ b/lib/webidl2.js
@@ -86,7 +86,7 @@
     }
   }
 
-  function parse(tokens, opt) {
+  function parse(tokens) {
     let line = 1;
     tokens = tokens.slice();
     const names = new Map();
@@ -656,8 +656,7 @@
           ret.members.push(cnt);
           continue;
         }
-        const mem = (opt.allowNestedTypedefs && typedef()) ||
-          static_member() ||
+        const mem = static_member() ||
           stringifier() ||
           iterable() ||
           attribute() ||
@@ -926,10 +925,9 @@
   }
 
   const obj = {
-    parse(str, opt) {
-      if (!opt) opt = {};
+    parse(str) {
       const tokens = tokenise(str);
-      return parse(tokens, opt);
+      return parse(tokens);
     }
   };
 
diff --git a/test/syntax/opt/typedef-nested.json b/test/syntax/opt/typedef-nested.json
deleted file mode 100644
index f0794e74..00000000
--- a/test/syntax/opt/typedef-nested.json
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-    "allowNestedTypedefs": true
-}
\ No newline at end of file