diff --git a/testbench/app/index.html b/testbench/app/index.html
index 04319c2..e057d85 100644
--- a/testbench/app/index.html
+++ b/testbench/app/index.html
@@ -2,6 +2,10 @@
 <html lang="en">
   <head>
     <meta charset="UTF-8" />
+    <meta
+    http-equiv="Content-Security-Policy"
+    content="style-src 'self'"
+  />
     <title>react-scrollbars-custom</title>
   </head>
 
