diff --git a/vendor/libc/include/string.h b/vendor/libc/include/string.h
index 7e5e2b252..6d947858f 100644
--- a/vendor/libc/include/string.h
+++ b/vendor/libc/include/string.h
@@ -8,7 +8,7 @@ extern "C" {
 
 void *memcpy(void *, const void *, size_t);
 void *memset(void *, int, size_t);
-void *memmove(void *, void *, size_t);
+void *memmove(void *, const void *, size_t);
 int memcmp(const void *, const void *, size_t);
 void *memchr(const void *, int, size_t);