diff --git a/build/jam/ArchitectureRules b/build/jam/ArchitectureRules
index 7151d89187..d5ef98fbe3 100644
--- a/build/jam/ArchitectureRules
+++ b/build/jam/ArchitectureRules
@@ -723,7 +723,7 @@ rule ArchitectureSetupWarnings architecture
 	EnableWerror src preferences ;
 	EnableWerror src servers ;
 	EnableWerror src system boot ;
-#	EnableWerror src system kernel ;
+	EnableWerror src system kernel ;
 	EnableWerror src system libroot add-ons ;
 	EnableWerror src system libroot os ;
 	EnableWerror src system libroot posix locale ;