diff --git a/sys/cddl/compat/opensolaris/sys/types.h b/sys/cddl/compat/opensolaris/sys/types.h
index 069ad45b2f32..e863e4b7082b 100644
--- a/sys/cddl/compat/opensolaris/sys/types.h
+++ b/sys/cddl/compat/opensolaris/sys/types.h
@@ -34,6 +34,10 @@
  */
 
 #include <sys/stdint.h>
+
+typedef	int64_t		clock_t;
+#define	_CLOCK_T_DECLARED
+
 #include_next <sys/types.h>
 
 #define	MAXNAMELEN	256