Index: sys/compat/netbsd32/netbsd32.h
===================================================================
RCS file: /cvsroot/src/sys/compat/netbsd32/netbsd32.h,v
retrieving revision 1.127
diff -u -r1.127 netbsd32.h
--- sys/compat/netbsd32/netbsd32.h	3 Oct 2019 22:16:53 -0000	1.127
+++ sys/compat/netbsd32/netbsd32.h	18 Nov 2019 11:11:51 -0000
@@ -162,6 +162,10 @@
 typedef uint64_t netbsd32_uint64 NETBSD32_INT64_ALIGN;
 #undef NETBSD32_INT64_ALIGN
 
+/* Type used in siginfo, avoids circular dependencies between headers. */
+CTASSERT(sizeof(netbsd32_uint64) == sizeof(netbsd32_siginfo_uint64));
+CTASSERT(__alignof__(netbsd32_uint64) == __alignof__(netbsd32_siginfo_uint64));
+
 /*
  * all pointers are netbsd32_pointer_t (defined in <machine/netbsd32_machdep.h>)
  */
Index: sys/compat/sys/siginfo.h
===================================================================
RCS file: /cvsroot/src/sys/compat/sys/siginfo.h,v
retrieving revision 1.8
diff -u -r1.8 siginfo.h
--- sys/compat/sys/siginfo.h	30 Sep 2019 21:13:33 -0000	1.8
+++ sys/compat/sys/siginfo.h	18 Nov 2019 11:11:51 -0000
@@ -34,6 +34,14 @@
 
 #ifdef _KERNEL
 
+/* Avoids circular dependency with machine/netbsd32_machdep.h */
+#if defined(__x86_64__)
+#define NETBSD32_SIGINFO_UINT64_ALIGN __attribute__((__aligned__(4)))
+#else
+#define NETBSD32_SIGINFO_UINT64_ALIGN __attribute__((__aligned__(8)))
+#endif
+typedef uint64_t netbsd32_siginfo_uint64 NETBSD32_SIGINFO_UINT64_ALIGN;
+
 typedef union sigval32 {
 	int sival_int;
 	uint32_t sival_ptr;
@@ -73,7 +81,7 @@
 			int	_sysnum;
 			int	_retval[2];
 			int	_error;
-			uint64_t _args[8]; /* SYS_MAXSYSARGS */
+			netbsd32_siginfo_uint64 _args[8]; /* SYS_MAXSYSARGS */
 		} _syscall;
 
 		struct {