diff --git a/.prettierignore b/.prettierignore
index 62fe6a45b95..a4a5e8ada89 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -1,6 +1,3 @@
-/config/
 /node_modules/
 /public/
 /vendor/
-karma.config.js
-webpack.config.js
diff --git a/.prettierrc b/.prettierrc
index 5e2863a11f6..748cfcae65f 100644
--- a/.prettierrc
+++ b/.prettierrc
@@ -1,5 +1,13 @@
 {
   "printWidth": 100,
   "singleQuote": true,
-  "trailingComma": "all"
+  "trailingComma": "es5",
+  "overrides": [
+    {
+      "files": ["app/assets/javascripts/*", "spec/javascripts/*"],
+      "options": {
+        "trailingComma": "all"
+      }
+    }
+  ]
 }