diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index f44a4fb..8d484a5 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1440,8 +1440,8 @@
   // is specified, or -std is set to a conforming mode.
   // Trigraphs are disabled by default in c++1z onwards.
   Opts.Trigraphs = !Opts.GNUMode && !Opts.MSVCCompat && !Opts.CPlusPlus1z;
-  if (Args.hasArg(OPT_trigraphs))
-    Opts.Trigraphs = 1;
+  Opts.Trigraphs =
+      Args.hasFlag(OPT_ftrigraphs, OPT_fno_trigraphs, Opts.Trigraphs);
 
   Opts.DollarIdents = Args.hasFlag(OPT_fdollars_in_identifiers,
                                    OPT_fno_dollars_in_identifiers,