diff --git a/include/llvm/Support/Compiler.h b/include/llvm/Support/Compiler.h
index 1edcd45bc3b..8ede85539b4 100644
--- a/include/llvm/Support/Compiler.h
+++ b/include/llvm/Support/Compiler.h
@@ -104,14 +104,13 @@
 /// public:
 ///   ...
 /// };
-#if __has_feature(cxx_deleted_functions) || \
-    defined(__GXX_EXPERIMENTAL_CXX0X__) || LLVM_MSC_PREREQ(1800)
+#if __has_feature(cxx_deleted_functions) || LLVM_MSC_PREREQ(1800)
 #define LLVM_DELETED_FUNCTION = delete
 #else
 #define LLVM_DELETED_FUNCTION
 #endif
 
-#if __has_feature(cxx_constexpr) || defined(__GXX_EXPERIMENTAL_CXX0X__)
+#if __has_feature(cxx_constexpr)
 # define LLVM_CONSTEXPR constexpr
 #else
 # define LLVM_CONSTEXPR
@@ -326,8 +325,7 @@
 /// \macro LLVM_EXPLICIT
 /// \brief Expands to explicit on compilers which support explicit conversion
 /// operators. Otherwise expands to nothing.
-#if __has_feature(cxx_explicit_conversions) || \
-    defined(__GXX_EXPERIMENTAL_CXX0X__) || LLVM_MSC_PREREQ(1800)
+#if __has_feature(cxx_explicit_conversions) || LLVM_MSC_PREREQ(1800)
 #define LLVM_EXPLICIT explicit
 #else
 #define LLVM_EXPLICIT