diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 918f0d9715e7..0d6cb3020568 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1529,7 +1529,7 @@ void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
   if (Args.hasFlag(options::OPT_mrelax_all,
                     options::OPT_mno_relax_all,
                     !IsOpt))
-    CmdArgs.push_back("-mrelax-all");
+    CmdArgs.push_back("-relax-all");
 
   // FIXME: Add -force_cpusubtype_ALL support, once we have it.