diff --git a/tools/build/cross-build/include/linux/sys/types.h b/tools/build/cross-build/include/linux/sys/types.h
index 222560167a71..2e09cbb62271 100644
--- a/tools/build/cross-build/include/linux/sys/types.h
+++ b/tools/build/cross-build/include/linux/sys/types.h
@@ -1,49 +1,70 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright 2018-2020 Alex Richardson <arichardson@FreeBSD.org>
  *
  * This software was developed by SRI International and the University of
  * Cambridge Computer Laboratory (Department of Computer Science and
  * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
  * DARPA SSITH research programme.
  *
  * This software was developed by SRI International and the University of
  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
  * ("CTSRD"), as part of the DARPA CRASH research programme.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 #pragma once
 
+#include <sys/cdefs.h> /* FreeBSD source assumes sys/types.h includes this */
+/*
+ * MUSL doesn't define the __intXX_t that FreeBSD does, but many of our headers
+ * assume that will always be present. Define them here. We assume !defined
+ * __GLIBC__ is musl since musl doesn't have a define to key off of. Thesee
+ * typedefs look backwards, but it's not circular because MUSL never defines the
+ * __*int*_t. Also, we don't have to work in the kernel, so it's OK to include
+ * stdint.h here.
+ */
+#ifndef __GLIBC__
+#include <stdint.h>
+typedef int64_t  __int64_t;
+typedef int32_t  __int32_t;
+typedef int16_t  __int16_t;
+typedef int8_t   __int8_t;
+typedef uint64_t __uint64_t;
+typedef uint32_t __uint32_t;
+typedef uint16_t __uint16_t;
+typedef uint8_t  __uint8_t;
+#endif
+
 #include_next <sys/types.h>
 
 /*
  * stddef.h for both gcc and clang will define __size_t when size_t has
  * been defined (except on *BSD where it doesn't touch __size_t). So if
  * we're building on Linux, we know that if that's not defined, we have
  * to typedef __size_t for FreeBSD's use of __size_t in places to work
  * during bootstrapping.
  */
 #ifndef __size_t
 typedef __SIZE_TYPE__ __size_t;
 #endif