diff --git a/.gitmodules b/.gitmodules
index 31948216..405a88e5 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -517,3 +517,6 @@
 	path = vendor/grammars/ruby.tmbundle
 	url = https://github.com/aroben/ruby.tmbundle
 	branch = pl
+[submodule "vendor/grammars/IDL-Syntax"]
+	path = vendor/grammars/IDL-Syntax
+	url = https://github.com/andik/IDL-Syntax
diff --git a/grammars.yml b/grammars.yml
index aaf83491..d6c679ff 100644
--- a/grammars.yml
+++ b/grammars.yml
@@ -33,6 +33,8 @@ vendor/grammars/Docker.tmbundle:
 - source.dockerfile
 vendor/grammars/Handlebars:
 - text.html.handlebars
+vendor/grammars/IDL-Syntax:
+- source.webidl
 vendor/grammars/Isabelle.tmbundle:
 - source.isabelle.root
 - source.isabelle.theory
diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index d69b072a..aa263926 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -3057,7 +3057,7 @@ WebIDL:
   type: programming
   extensions:
   - .webidl
-  tm_scope: none
+  tm_scope: source.webidl
   ace_mode: text
 
 XC:
diff --git a/vendor/grammars/IDL-Syntax b/vendor/grammars/IDL-Syntax
new file mode 160000
index 00000000..9473b7fa
--- /dev/null
+++ b/vendor/grammars/IDL-Syntax
@@ -0,0 +1 @@
+Subproject commit 9473b7faaf709740d08d84823f9e86b2ad585f62