diff --git a/curriculum/challenges/english/01-responsive-web-design/basic-css/create-a-custom-css-variable.english.md b/curriculum/challenges/english/01-responsive-web-design/basic-css/create-a-custom-css-variable.english.md
index f2d7af9549..464217874d 100644
--- a/curriculum/challenges/english/01-responsive-web-design/basic-css/create-a-custom-css-variable.english.md
+++ b/curriculum/challenges/english/01-responsive-web-design/basic-css/create-a-custom-css-variable.english.md
@@ -30,7 +30,7 @@ In the <code>penguin</code> class, create a variable name <code>--penguin-skin</
 ```yml
 tests:
   - text: <code>penguin</code> class should declare the <code>--penguin-skin</code> variable and assign it to <code>gray</code>.
-    testString: assert(code.match(/.penguin\s*?{[\s\S]*--penguin-skin\s*?:\s*?gray\s*?;[\s\S]*}/gi));
+    testString: assert(code.match(/\.penguin\s*\{[^{}]*?--penguin-skin\s*:\s*gr[ae]y\s*;[^{}]*?\}/gi));
 
 ```