diff --git a/llvm/lib/TextAPI/Platform.cpp b/llvm/lib/TextAPI/Platform.cpp
--- a/llvm/lib/TextAPI/Platform.cpp
+++ b/llvm/lib/TextAPI/Platform.cpp
@@ -29,7 +29,7 @@
   case PlatformKind::watchOS:
     return WantSim ? PlatformKind::watchOSSimulator : PlatformKind::watchOS;
   }
-  llvm_unreachable("Unknown llvm.MachO.PlatformKind enum");
+  llvm_unreachable("Unknown llvm::MachO::PlatformKind enum");
 }
 
 PlatformKind mapToPlatformKind(const Triple &Target) {
@@ -87,7 +87,7 @@
   case PlatformKind::driverKit:
     return "DriverKit";
   }
-  llvm_unreachable("Unknown llvm.MachO.PlatformKind enum");
+  llvm_unreachable("Unknown llvm::MachO::PlatformKind enum");
 }
 
 PlatformKind getPlatformFromName(StringRef Name) {