diff --git a/libc/include/string.h b/libc/include/string.h
index 643132d..0a1d653 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -25,8 +25,9 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
-#ifndef _STRING_H_
-#define _STRING_H_
+
+#ifndef _STRING_H
+#define _STRING_H
 
 #include <sys/cdefs.h>
 #include <stddef.h>
@@ -92,6 +93,20 @@
 extern int    strcoll_l(const char *, const char *, locale_t) __purefunc;
 extern size_t strxfrm_l(char* __restrict, const char* __restrict, size_t, locale_t);
 
+#if defined(__USE_GNU) && !defined(__bionic_using_posix_basename)
+/*
+ * glibc has a basename in <string.h> that's different to the POSIX one in <libgen.h>.
+ * It doesn't modify its argument, and in C++ it's const-correct.
+ */
+#if defined(__cplusplus)
+extern "C++" char* basename(char*) __RENAME(__gnu_basename) __nonnull((1));
+extern "C++" const char* basename(const char*) __RENAME(__gnu_basename) __nonnull((1));
+#else
+extern char* basename(const char*) __RENAME(__gnu_basename) __nonnull((1));
+#endif
+#define __bionic_using_gnu_basename
+#endif
+
 #if defined(__BIONIC_FORTIFY)
 
 __BIONIC_FORTIFY_INLINE
@@ -289,4 +304,4 @@
 
 __END_DECLS
 
-#endif /* _STRING_H_ */
+#endif /* _STRING_H */