diff --git a/clang/lib/Driver/ToolChains/Arch/PPC.cpp b/clang/lib/Driver/ToolChains/Arch/PPC.cpp
index 8824253cc98467..4287d415346935 100644
--- a/clang/lib/Driver/ToolChains/Arch/PPC.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/PPC.cpp
@@ -85,7 +85,12 @@ std::string ppc::getPPCTuneCPU(const ArgList &Args, const llvm::Triple &T) {
 }
 
 /// Get the (LLVM) name of the PowerPC cpu we are targeting.
-std::string ppc::getPPCTargetCPU(const ArgList &Args, const llvm::Triple &T) {
+std::string ppc::getPPCTargetCPU(const Driver &D, const ArgList &Args,
+                                 const llvm::Triple &T) {
+  if (const Arg *A = Args.getLastArg(clang::driver::options::OPT_march_EQ)) {
+    D.Diag(diag::err_drv_unsupported_opt_for_target)
+        << A->getSpelling() << T.getTriple();
+  }
   if (Arg *A = Args.getLastArg(clang::driver::options::OPT_mcpu_EQ))
     return normalizeCPUName(A->getValue(), T);
   return getPPCGenericTargetCPU(T);
diff --git a/clang/lib/Driver/ToolChains/Arch/PPC.h b/clang/lib/Driver/ToolChains/Arch/PPC.h
index 97ac4508385216..ec5b3c8140b660 100644
--- a/clang/lib/Driver/ToolChains/Arch/PPC.h
+++ b/clang/lib/Driver/ToolChains/Arch/PPC.h
@@ -35,7 +35,7 @@ enum class ReadGOTPtrMode {
 
 FloatABI getPPCFloatABI(const Driver &D, const llvm::opt::ArgList &Args);
 
-std::string getPPCTargetCPU(const llvm::opt::ArgList &Args,
+std::string getPPCTargetCPU(const Driver &D, const llvm::opt::ArgList &Args,
                             const llvm::Triple &T);
 std::string getPPCTuneCPU(const llvm::opt::ArgList &Args,
                           const llvm::Triple &T);
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index c179c4152cee4b..dc46b625bb6767 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -410,7 +410,7 @@ std::string tools::getCPUName(const Driver &D, const ArgList &Args,
   case llvm::Triple::ppcle:
   case llvm::Triple::ppc64:
   case llvm::Triple::ppc64le:
-    return ppc::getPPCTargetCPU(Args, T);
+    return ppc::getPPCTargetCPU(D, Args, T);
 
   case llvm::Triple::csky:
     if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
diff --git a/clang/test/Driver/ppc-cpus.c b/clang/test/Driver/ppc-cpus.c
index 050512f9d87be8..4edd83b4d6d282 100644
--- a/clang/test/Driver/ppc-cpus.c
+++ b/clang/test/Driver/ppc-cpus.c
@@ -39,3 +39,6 @@
 // RUN: %clang -### -c -target powerpc64 %s -mcpu=405     2>&1 | FileCheck %s --check-prefix=GENERIC
 //
 // GENERIC: "-target-cpu" "ppc64"
+
+// RUN: %clang -### -c --target=powerpc64 %s -march=generic 2>&1 | FileCheck --check-prefix=MARCH %s
+// MARCH: error: unsupported option '-march=' for target 'powerpc64'