diff --git a/.pr-preview.json b/.pr-preview.json
index 49b06777..5ca47f73 100644
--- a/.pr-preview.json
+++ b/.pr-preview.json
@@ -1,4 +1,7 @@
 {
     "src_file": "index.bs",
-    "type": "bikeshed"
+    "type": "bikeshed",
+    "post_processing": {
+        "name": "webidl-grammar"
+    }
 }
diff --git a/Makefile b/Makefile
index 93d04af9..5589e084 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,14 @@
-bs := $(shell command -v bikeshed 2> /dev/null)
+bs_installed  := $(shell command -v bikeshed 2> /dev/null)
+npm_installed := $(shell command -v npm 2> /dev/null)
+pp_webidl_installed := $(shell npm ls webidl-grammar-post-processor --parseable --depth=0 2> /dev/null)
 
 all : index.html
 
 index.html : index.bs
-ifdef bs
+ifdef bs_installed
 	bikeshed spec index.bs
 else
-	@echo Cannot find a local version of Bikeshed. To install it, visit:
+	@echo Can't find a local version of Bikeshed. To install it, visit:
 	@echo
 	@echo https://github.com/tabatkins/bikeshed/blob/master/docs/install.md
 	@echo
@@ -14,6 +16,18 @@ else
 	@echo This will fail if you are not connected to the network.
 	curl https://api.csswg.org/bikeshed/ -F file=@index.bs > index.html
 endif
+ifdef pp_webidl_installed
+	npm run pp-webidl -- --input index.html
+else ifdef npm_installed
+	npm install
+	npm run pp-webidl -- --input index.html
+else
+	@echo You need node.js and npm to apply post-processing. To install it, visit:
+	@echo
+	@echo https://nodejs.org/en/download/
+	@echo
+	@echo Until then, post-processing will be done dynamically, in JS, on page load.
+endif
 
 clean :
 	rm -f index.html
diff --git a/deploy.sh b/deploy.sh
index 7e767dbe..717f679a 100755
--- a/deploy.sh
+++ b/deploy.sh
@@ -7,6 +7,7 @@ TARGET_BRANCH="gh-pages"
 function doCompile {
   curl https://api.csswg.org/bikeshed/ -F file=@index.bs > out/index.html
   node ./check-grammar.js ./out/index.html
+  npm run pp-webidl -- --input ./out/index.html
 }
 
 # Pull requests and commits to other branches shouldn't try to deploy, just build to verify
diff --git a/index.bs b/index.bs
index 00911b01..73e8be55 100644
--- a/index.bs
+++ b/index.bs
@@ -13632,7 +13632,7 @@ The following conformance classes are defined by this specification:
     criteria in this specification that apply to implementations for the ECMAScript
     language binding.
 
-<script>
+<script class="remove">
     // Grammar
     (function() {
         function wrap(s) { return "<pre class=grammar>" + s + "</pre>"; }
@@ -13661,8 +13661,9 @@ The following conformance classes are defined by this specification:
         });
         document.querySelector("div[data-fill-with=\"grammar-index\"]").innerHTML = wrap(output);
     })();
+</script>
 
-
+<script>
     // Rotated Table Headers
     /*! modernizr 3.3.1 (Custom Build) | MIT *
      * https://modernizr.com/download/?-csstransforms-setclasses !*/
diff --git a/package.json b/package.json
index 854dafcb..296fc6db 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,10 @@
   "description": "Checks that the WebIDL grammar is LL(1)",
   "devDependencies": {
     "jsdom": "^11.3.0",
-    "syntax-cli": "0.0.97"
+    "syntax-cli": "0.0.97",
+    "webidl-grammar-post-processor": "^0.4.0"
+  },
+  "scripts": {
+    "pp-webidl": "pp-webidl"
   }
 }