diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -634,8 +634,9 @@
 
   // If target is MIPS adjust the target triple
   // accordingly to provided ABI name.
-  A = Args.getLastArg(options::OPT_mabi_EQ);
+  A = Args.getLastArgNoClaim(options::OPT_mabi_EQ);
   if (A && Target.isMIPS()) {
+    A->claim();
     StringRef ABIName = A->getValue();
     if (ABIName == "32") {
       Target = Target.get32BitArchVariant();
diff --git a/clang/test/Driver/mabi.c b/clang/test/Driver/mabi.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Driver/mabi.c
@@ -0,0 +1,6 @@
+// RUN: %clang -target i386-unknown-linux -mabi=ms -S %s -### 2>&1 | FileCheck --check-prefix=CHECK %s
+
+int f() {
+  // CHECK: warning: argument unused during compilation: '-mabi=ms'
+  return 0;
+}