1 files changed, 6 insertions, 1 deletions
diff --git a/lib/Support/Windows/WindowsSupport.h b/lib/Support/Windows/WindowsSupport.h
index 1d1cedcce2993..5bb0b8d2d7887 100644
--- a/lib/Support/Windows/WindowsSupport.h
+++ b/lib/Support/Windows/WindowsSupport.h
@@ -19,6 +19,9 @@
 //===          is guaranteed to work on *all* Win32 variants.
 //===----------------------------------------------------------------------===//
 
+#ifndef LLVM_SUPPORT_WINDOWSSUPPORT_H
+#define LLVM_SUPPORT_WINDOWSSUPPORT_H
+
 // mingw-w64 tends to define it as 0x0502 in its headers.
 #undef _WIN32_WINNT
 #undef _WIN32_IE
@@ -89,7 +92,7 @@ public:
   }
 
   // True if Handle is valid.
-  LLVM_EXPLICIT operator bool() const {
+  explicit operator bool() const {
     return HandleTraits::IsValid(Handle) ? true : false;
   }
 
@@ -178,3 +181,5 @@ std::error_code UTF16ToCurCP(const wchar_t *utf16, size_t utf16_len,
 } // end namespace windows
 } // end namespace sys
 } // end namespace llvm.
+
+#endif