diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index 93aeae10032..5b945d12209 100755
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -51,7 +51,6 @@ check_include_file(ndir.h HAVE_NDIR_H)
 if( NOT PURE_WINDOWS )
   check_include_file(pthread.h HAVE_PTHREAD_H)
 endif()
-check_include_file(sanitizer/msan_interface.h HAVE_SANITIZER_MSAN_INTERFACE_H)
 check_include_file(signal.h HAVE_SIGNAL_H)
 check_include_file(stdint.h HAVE_STDINT_H)
 check_include_file(sys/dir.h HAVE_SYS_DIR_H)
diff --git a/include/llvm/Config/llvm-config.h.cmake b/include/llvm/Config/llvm-config.h.cmake
index 80616ef9508..2b828a1ffb0 100644
--- a/include/llvm/Config/llvm-config.h.cmake
+++ b/include/llvm/Config/llvm-config.h.cmake
@@ -121,7 +121,4 @@
 /* Minor version of the LLVM API */
 #cmakedefine LLVM_VERSION_MINOR ${LLVM_VERSION_MINOR}
 
-/* Define to 1 if you have the <sanitizer/msan_interface.h> header file. */
-#cmakedefine HAVE_SANITIZER_MSAN_INTERFACE_H ${HAVE_SANITIZER_MSAN_INTERFACE_H}
-
 #endif
diff --git a/include/llvm/Support/Compiler.h b/include/llvm/Support/Compiler.h
index 49f29954349..d7621a0513b 100644
--- a/include/llvm/Support/Compiler.h
+++ b/include/llvm/Support/Compiler.h
@@ -349,19 +349,15 @@
 # define LLVM_FUNCTION_NAME __func__
 #endif
 
-#if defined(HAVE_SANITIZER_MSAN_INTERFACE_H)
-# include <sanitizer/msan_interface.h>
-#else
-# define __msan_allocated_memory(p, size)
-# define __msan_unpoison(p, size)
-#endif
-
 /// \macro LLVM_MEMORY_SANITIZER_BUILD
 /// \brief Whether LLVM itself is built with MemorySanitizer instrumentation.
 #if __has_feature(memory_sanitizer)
 # define LLVM_MEMORY_SANITIZER_BUILD 1
+# include <sanitizer/msan_interface.h>
 #else
 # define LLVM_MEMORY_SANITIZER_BUILD 0
+# define __msan_allocated_memory(p, size)
+# define __msan_unpoison(p, size)
 #endif
 
 /// \macro LLVM_ADDRESS_SANITIZER_BUILD