diff --git a/lib/libzfs_core/libzfs_core.c b/lib/libzfs_core/libzfs_core.c
index d35ea523e0..50b1b9dec2 100644
--- a/lib/libzfs_core/libzfs_core.c
+++ b/lib/libzfs_core/libzfs_core.c
@@ -97,7 +97,7 @@ static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
 static int g_refcount;
 
 #ifdef ZFS_DEBUG
-static zfs_ioc_t fail_ioc_cmd;
+static zfs_ioc_t fail_ioc_cmd = ZFS_IOC_LAST;
 static zfs_errno_t fail_ioc_err;
 
 static void
@@ -118,7 +118,7 @@ libzfs_core_debug_ioc(void)
 	 * cannot checkpoint 'tank': the loaded zfs module does not support
 	 * this operation. A reboot may be required to enable this operation.
 	 */
-	if (fail_ioc_cmd == 0) {
+	if (fail_ioc_cmd == ZFS_IOC_LAST) {
 		char *ioc_test = getenv("ZFS_IOC_TEST");
 		unsigned int ioc_num = 0, ioc_err = 0;