diff --git a/lib/secure_headers/headers/policy_management.rb b/lib/secure_headers/headers/policy_management.rb
index 1c290924..102ba204 100644
--- a/lib/secure_headers/headers/policy_management.rb
+++ b/lib/secure_headers/headers/policy_management.rb
@@ -96,7 +96,6 @@ def self.included(base)
 
     FIREFOX_UNSUPPORTED_DIRECTIVES = [
       BLOCK_ALL_MIXED_CONTENT,
-      CHILD_SRC,
       PLUGIN_TYPES
     ].freeze