diff --git a/zlib/zutil.h b/zlib/zutil.h
index 48dd7feba..8d628c7c2 100644
--- a/zlib/zutil.h
+++ b/zlib/zutil.h
@@ -168,7 +168,8 @@ extern z_const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
 #endif
 
 /* provide prototypes for these when building zlib without LFS */
-#if !defined(_WIN32) && \
+#if 0 && /* NASM hack */                                         \
+    !defined(_WIN32) &&                                          \
     (!defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0)
     ZEXTERN uLong ZEXPORT adler32_combine64(uLong, uLong, z_off_t);
     ZEXTERN uLong ZEXPORT crc32_combine64(uLong, uLong, z_off_t);