diff --git a/pkgs/puppet-editor-services/Gemfile b/pkgs/puppet-editor-services/Gemfile
index 3ea93be..1c261a9 100644
--- a/pkgs/puppet-editor-services/Gemfile
+++ b/pkgs/puppet-editor-services/Gemfile
@@ -1,3 +1,4 @@
 source 'https://rubygems.org'
 
 gem 'puppet-editor-services'
+gem 'racc'
diff --git a/pkgs/puppet-editor-services/Gemfile.lock b/pkgs/puppet-editor-services/Gemfile.lock
index ccd0fbb..440e874 100644
--- a/pkgs/puppet-editor-services/Gemfile.lock
+++ b/pkgs/puppet-editor-services/Gemfile.lock
@@ -52,6 +52,7 @@ GEM
     puppetfile-resolver (0.6.3)
       molinillo (~> 0.6)
       semantic_puppet (~> 1.0)
+    racc (1.8.1)
     reline (0.6.2)
       io-console (~> 0.5)
     rgen (0.10.2)
@@ -66,6 +67,7 @@ PLATFORMS
 
 DEPENDENCIES
   puppet-editor-services
+  racc
 
 BUNDLED WITH
    2.6.6
diff --git a/pkgs/puppet-editor-services/gemset.nix b/pkgs/puppet-editor-services/gemset.nix
index 343fdcf..d9a7f12 100644
--- a/pkgs/puppet-editor-services/gemset.nix
+++ b/pkgs/puppet-editor-services/gemset.nix
@@ -289,6 +289,16 @@
     };
     version = "0.6.3";
   };
+  racc = {
+    groups = [ "default" ];
+    platforms = [ ];
+    source = {
+      remotes = [ "https://rubygems.org" ];
+      sha256 = "0byn0c9nkahsl93y9ln5bysq4j31q8xkf2ws42swighxd4lnjzsa";
+      type = "gem";
+    };
+    version = "1.8.1";
+  };
   reline = {
     dependencies = [ "io-console" ];
     groups = [ "default" ];