diff --git a/libc/include/string.h b/libc/include/string.h
index f3dca1b..fb24808 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -115,11 +115,7 @@
 
 __BIONIC_FORTIFY_INLINE
 void* memcpy(void* __restrict dest, const void* __restrict src, size_t copy_amount) {
-    char *d = (char *) dest;
-    const char *s = (const char *) src;
-    size_t d_len = __bos0(d);
-
-    return __builtin___memcpy_chk(dest, src, copy_amount, d_len);
+    return __builtin___memcpy_chk(dest, src, copy_amount, __bos0(dest));
 }
 
 __BIONIC_FORTIFY_INLINE