diff --git a/actionpack/lib/action_dispatch/http/content_security_policy.rb b/actionpack/lib/action_dispatch/http/content_security_policy.rb
index 82d348fa226632191710f73689dfa9bf9418df02..17e72b46ff4a86d424320696226cff854d819046 100644
--- a/actionpack/lib/action_dispatch/http/content_security_policy.rb
+++ b/actionpack/lib/action_dispatch/http/content_security_policy.rb
@@ -229,7 +229,6 @@ def apply_mapping(source)
       def build_directives(context, nonce)
         @directives.map do |directive, sources|
           if sources.is_a?(Array)
-            "#{directive} #{build_directive(sources, context).join(' ')}"
             if nonce && nonce_directive?(directive)
               "#{directive} #{build_directive(sources, context).join(' ')} 'nonce-#{nonce}'"
             else