diff --git a/include/cstring b/include/cstring
index d60b9923c..5e1837202 100644
--- a/include/cstring
+++ b/include/cstring
@@ -78,30 +78,8 @@ using ::strcmp;
 using ::strncmp;
 using ::strcoll;
 using ::strxfrm;
-
-using ::memchr;
-
-using ::strchr;
-
 using ::strcspn;
-
-using ::strpbrk;
-
-using ::strrchr;
-
 using ::strspn;
-
-using ::strstr;
-
-// MSVCRT, GNU libc and its derivates already have the correct prototype in <string.h> #ifdef __cplusplus
-#if !defined(__GLIBC__) && !defined(_LIBCPP_MSVCRT) && !defined(__sun__) && !defined(_STRING_H_CPLUSPLUS_98_CONFORMANCE_)
-inline _LIBCPP_INLINE_VISIBILITY       char* strchr(      char* __s, int __c) {return ::strchr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY       char* strpbrk(      char* __s1, const char* __s2) {return ::strpbrk(__s1, __s2);}
-inline _LIBCPP_INLINE_VISIBILITY       char* strrchr(      char* __s, int __c) {return ::strrchr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY       void* memchr(      void* __s, int __c, size_t __n) {return ::memchr(__s, __c, __n);}
-inline _LIBCPP_INLINE_VISIBILITY       char* strstr(      char* __s1, const char* __s2) {return ::strstr(__s1, __s2);}
-#endif
-
 #ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
 using ::strtok;
 #endif
@@ -109,6 +87,33 @@ using ::memset;
 using ::strerror;
 using ::strlen;
 
+// MSVCRT, GNU libc and its derivates already have the correct prototype in
+// <string.h> if __cplusplus is defined. This macro can be defined by users if
+// their C library provides the right signature.
+#if defined(__GLIBC__) || defined(_LIBCPP_MSVCRT) || defined(__sun__) || \
+    defined(_STRING_H_CPLUSPLUS_98_CONFORMANCE_)
+#define _LIBCPP_STRING_H_HAS_CONST_OVERLOADS
+#endif
+
+#ifdef _LIBCPP_STRING_H_HAS_CONST_OVERLOADS
+using ::strchr;
+using ::strpbrk;
+using ::strrchr;
+using ::memchr;
+using ::strstr;
+#else
+inline _LIBCPP_INLINE_VISIBILITY const char* strchr(const char* __s, int __c) {return ::strchr(__s, __c);}
+inline _LIBCPP_INLINE_VISIBILITY       char* strchr(      char* __s, int __c) {return ::strchr(__s, __c);}
+inline _LIBCPP_INLINE_VISIBILITY const char* strpbrk(const char* __s1, const char* __s2) {return ::strpbrk(__s1, __s2);}
+inline _LIBCPP_INLINE_VISIBILITY       char* strpbrk(      char* __s1, const char* __s2) {return ::strpbrk(__s1, __s2);}
+inline _LIBCPP_INLINE_VISIBILITY const char* strrchr(const char* __s, int __c) {return ::strrchr(__s, __c);}
+inline _LIBCPP_INLINE_VISIBILITY       char* strrchr(      char* __s, int __c) {return ::strrchr(__s, __c);}
+inline _LIBCPP_INLINE_VISIBILITY const void* memchr(const void* __s, int __c, size_t __n) {return ::memchr(__s, __c, __n);}
+inline _LIBCPP_INLINE_VISIBILITY       void* memchr(      void* __s, int __c, size_t __n) {return ::memchr(__s, __c, __n);}
+inline _LIBCPP_INLINE_VISIBILITY const char* strstr(const char* __s1, const char* __s2) {return ::strstr(__s1, __s2);}
+inline _LIBCPP_INLINE_VISIBILITY       char* strstr(      char* __s1, const char* __s2) {return ::strstr(__s1, __s2);}
+#endif
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP_CSTRING
diff --git a/include/string.h b/include/string.h
new file mode 100644
index 000000000..c3b1e46ec
--- /dev/null
+++ b/include/string.h
@@ -0,0 +1,63 @@
+// -*- C++ -*-
+//===--------------------------- string.h ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_STRING_H
+#define _LIBCPP_STRING_H
+
+/*
+    string.h synopsis
+
+Macros:
+
+    NULL
+
+Types:
+
+    size_t
+
+void* memcpy(void* restrict s1, const void* restrict s2, size_t n);
+void* memmove(void* s1, const void* s2, size_t n);
+char* strcpy (char* restrict s1, const char* restrict s2);
+char* strncpy(char* restrict s1, const char* restrict s2, size_t n);
+char* strcat (char* restrict s1, const char* restrict s2);
+char* strncat(char* restrict s1, const char* restrict s2, size_t n);
+int memcmp(const void* s1, const void* s2, size_t n);
+int strcmp (const char* s1, const char* s2);
+int strncmp(const char* s1, const char* s2, size_t n);
+int strcoll(const char* s1, const char* s2);
+size_t strxfrm(char* restrict s1, const char* restrict s2, size_t n);
+const void* memchr(const void* s, int c, size_t n);
+      void* memchr(      void* s, int c, size_t n);
+const char* strchr(const char* s, int c);
+      char* strchr(      char* s, int c);
+size_t strcspn(const char* s1, const char* s2);
+const char* strpbrk(const char* s1, const char* s2);
+      char* strpbrk(      char* s1, const char* s2);
+const char* strrchr(const char* s, int c);
+      char* strrchr(      char* s, int c);
+size_t strspn(const char* s1, const char* s2);
+const char* strstr(const char* s1, const char* s2);
+      char* strstr(      char* s1, const char* s2);
+char* strtok(char* restrict s1, const char* restrict s2);
+void* memset(void* s, int c, size_t n);
+char* strerror(int errnum);
+size_t strlen(const char* s);
+
+*/
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#include_next <string.h>
+
+#endif  // _LIBCPP_STRING_H