diff --git a/include/sys/ioc_disk.h b/include/sys/ioc_disk.h
index 2f9250c35..f5650637d 100755
--- a/include/sys/ioc_disk.h
+++ b/include/sys/ioc_disk.h
@@ -12,6 +12,6 @@
 #define DIOCGETP	_IOR('d', 4, struct partition)
 #define DIOCEJECT	_IO ('d', 5)
 #define DIOCTIMEOUT	_IOW('d', 6, int)
-#define DIOCOPENCT	_IOR('c', 7, int)
+#define DIOCOPENCT	_IOR('d', 7, int)
 
 #endif /* _S_I_DISK_H */