diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index e79eea48605a5..4c4f68e8a728d 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -290,6 +290,8 @@ void ToolChain::addCommonFrontendArgs(const OutputInfo &OI,
   inputArgs.AddLastArg(arguments, options::OPT_enable_app_extension);
   inputArgs.AddLastArg(arguments, options::OPT_enable_app_extension_library);
   inputArgs.AddLastArg(arguments, options::OPT_enable_library_evolution);
+  inputArgs.AddLastArg(arguments, options::OPT_default_isolation);
+  inputArgs.AddLastArg(arguments, options::OPT_default_isolation_EQ);
   inputArgs.AddLastArg(arguments, options::OPT_require_explicit_availability);
   inputArgs.AddLastArg(arguments, options::OPT_require_explicit_availability_target);
   inputArgs.AddLastArg(arguments, options::OPT_require_explicit_availability_EQ);