1 files changed, 3 insertions, 5 deletions
diff --git a/actionpack/lib/action_dispatch/http/content_security_policy.rb b/actionpack/lib/action_dispatch/http/content_security_policy.rb
index d10d4faf3d..4883e23d24 100644
--- a/actionpack/lib/action_dispatch/http/content_security_policy.rb
+++ b/actionpack/lib/action_dispatch/http/content_security_policy.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "active_support/core_ext/object/deep_dup"
+
 module ActionDispatch #:nodoc:
   class ContentSecurityPolicy
     class Middleware
@@ -110,7 +112,7 @@ module ActionDispatch #:nodoc:
     end
 
     def initialize_copy(other)
-      @directives = copy_directives(other.directives)
+      @directives = other.directives.deep_dup
     end
 
     DIRECTIVES.each do |name, directive|
@@ -174,10 +176,6 @@ module ActionDispatch #:nodoc:
     end
 
     private
-      def copy_directives(directives)
-        directives.transform_values { |sources| sources.map(&:dup) }
-      end
-
       def apply_mappings(sources)
         sources.map do |source|
           case source