diff --git a/clang/tools/driver/cc1_main.cpp b/clang/tools/driver/cc1_main.cpp
--- a/clang/tools/driver/cc1_main.cpp
+++ b/clang/tools/driver/cc1_main.cpp
@@ -177,7 +177,7 @@
   // the target machine will handle the mcpu printing
   llvm::TargetOptions Options;
   std::unique_ptr<llvm::TargetMachine> TheTargetMachine(
-      TheTarget->createTargetMachine(TargetStr, "", "+cpuHelp", Options, None));
+      TheTarget->createTargetMachine(TargetStr, "", "+cpuhelp", Options, None));
   return 0;
 }
 
diff --git a/llvm/lib/MC/MCSubtargetInfo.cpp b/llvm/lib/MC/MCSubtargetInfo.cpp
--- a/llvm/lib/MC/MCSubtargetInfo.cpp
+++ b/llvm/lib/MC/MCSubtargetInfo.cpp
@@ -185,7 +185,7 @@
     // Check for help
     if (Feature == "+help")
       Help(ProcDesc, ProcFeatures);
-    else if (Feature == "+cpuHelp")
+    else if (Feature == "+cpuhelp")
       cpuHelp(ProcDesc);
     else
       ApplyFeatureFlag(Bits, Feature, ProcFeatures);