diff --git a/sys/sys/_stdint.h b/sys/sys/_stdint.h
--- a/sys/sys/_stdint.h
+++ b/sys/sys/_stdint.h
@@ -78,6 +78,16 @@
 typedef	__uintptr_t		uintptr_t;
 #define	_UINTPTR_T_DECLARED
 #endif
+#if defined(__BSD_VISIBLE) && __BSD_VISIBLE
+#ifndef _INT64PTR_T_DECLARED
+typedef	__int64ptr_t		int64ptr_t;
+#define	_INT64PTR_T_DECLARED
+#endif
+#ifndef _UINT64PTR_T_DECLARED
+typedef	__uint64ptr_t		uint64ptr_t;
+#define	_UINT64PTR_T_DECLARED
+#endif
+#endif
 #ifndef _INTMAX_T_DECLARED
 typedef	__intmax_t		intmax_t;
 #define	_INTMAX_T_DECLARED
diff --git a/sys/sys/_types.h b/sys/sys/_types.h
--- a/sys/sys/_types.h
+++ b/sys/sys/_types.h
@@ -70,18 +70,24 @@
 #ifdef __CHERI__
 typedef	__intcap_t	__intptr_t;
 typedef	__intcap_t	__intfptr_t;
+typedef	__intptr_t	__int64ptr_t;
 typedef	__uintcap_t	__uintptr_t;
 typedef	__uintcap_t	__uintfptr_t;
+typedef	__uintptr_t	__uint64ptr_t;
 #elif __SIZEOF_POINTER__ == 8
 typedef	__int64_t	__intptr_t;
 typedef	__int64_t	__intfptr_t;
+typedef	__int64_t	__int64ptr_t;
 typedef	__uint64_t	__uintptr_t;
 typedef	__uint64_t	__uintfptr_t;
+typedef	__uint64_t	__uint64ptr_t;
 #elif __SIZEOF_POINTER__ == 4
 typedef	__int32_t	__intptr_t;
 typedef	__int32_t	__intfptr_t;
+typedef	__int64_t	__int64ptr_t;
 typedef	__uint32_t	__uintptr_t;
 typedef	__uint32_t	__uintfptr_t;
+typedef	__uint64_t	__uint64ptr_t;
 #else
 #error unsupported pointer size
 #endif