diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 6d6dbfc..6d34425 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -2151,6 +2151,9 @@
 
   Opts.EmitMicrosoftInlineAsm = Args.hasArg(OPT_fenable_experimental_ms_inline_asm);
 
+  Opts.RetainCommentsFromSystemHeaders =
+      Args.hasArg(OPT_fretain_comments_from_system_headers);
+
   unsigned SSP = Args.getLastArgIntValue(OPT_stack_protector, 0, Diags);
   switch (SSP) {
   default: