diff --git a/llvm/lib/Support/Signals.cpp b/llvm/lib/Support/Signals.cpp
index 661f4d6..bcd350f 100644
--- a/llvm/lib/Support/Signals.cpp
+++ b/llvm/lib/Support/Signals.cpp
@@ -125,7 +125,7 @@
 
   Optional<StringRef> Redirects[] = {InputFile.str(), OutputFile.str(), llvm::None};
   const char *Args[] = {"llvm-symbolizer", "--functions=linkage", "--inlining",
-#ifdef LLVM_ON_WIN32
+#ifdef _WIN32
                         // Pass --relative-address on Windows so that we don't
                         // have to add ImageBase from PE file.
                         // FIXME: Make this the default for llvm-symbolizer.
@@ -180,6 +180,6 @@
 #ifdef LLVM_ON_UNIX
 #include "Unix/Signals.inc"
 #endif
-#ifdef LLVM_ON_WIN32
+#ifdef _WIN32
 #include "Windows/Signals.inc"
 #endif