diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 89fd70a..eecd976 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -102,7 +102,8 @@
     Res.push_back("-disable-red-zone");
   if (!Opts.MergeAllConstants)
     Res.push_back("-fno-merge-all-constants");
-  // NoCommon is only derived.
+  if (Opts.NoCommon)
+    Res.push_back("-fno-common");
   if (Opts.NoImplicitFloat)
     Res.push_back("-no-implicit-float");
   if (Opts.OptimizeSize) {