diff --git a/libc/include/string.h b/libc/include/string.h
index 8e472e7..5259c15 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -208,6 +208,7 @@
     return __strlcat_chk(dest, src, size, bos);
 }
 
+#if !defined(__clang__)
 __purefunc extern size_t __strlen_real(const char *)
     __asm__(__USER_LABEL_PREFIX__ "strlen");
 extern size_t __strlen_chk(const char *, size_t);
@@ -223,6 +224,7 @@
 
     return __strlen_chk(s, bos);
 }
+#endif  /* !defined(__clang__) */
 
 
 #endif /* defined(__BIONIC_FORTIFY_INLINE) */