diff --git a/lib/util/io_channel.c b/lib/util/io_channel.c
index 6898d67e3..97681c560 100644
--- a/lib/util/io_channel.c
+++ b/lib/util/io_channel.c
@@ -303,6 +303,10 @@ spdk_io_device_register(void *io_device, spdk_io_channel_create_cb create_cb,
 {
 	struct io_device *dev, *tmp;
 
+	assert(io_device != NULL);
+	assert(create_cb != NULL);
+	assert(destroy_cb != NULL);
+
 	dev = calloc(1, sizeof(struct io_device));
 	if (dev == NULL) {
 		SPDK_ERRLOG("could not allocate io_device\n");
diff --git a/test/unit/lib/util/io_channel.c/io_channel_ut.c b/test/unit/lib/util/io_channel.c/io_channel_ut.c
index efda52d8f..0febd151d 100644
--- a/test/unit/lib/util/io_channel.c/io_channel_ut.c
+++ b/test/unit/lib/util/io_channel.c/io_channel_ut.c
@@ -353,12 +353,6 @@ destroy_cb_2(void *io_device, void *ctx_buf)
 	g_destroy_cb_calls++;
 }
 
-static int
-create_cb_null(void *io_device, void *ctx_buf)
-{
-	return -1;
-}
-
 static void
 channel(void)
 {
@@ -368,7 +362,6 @@ channel(void)
 	spdk_allocate_thread(_send_msg, NULL, NULL, NULL, "thread0");
 	spdk_io_device_register(&device1, create_cb_1, destroy_cb_1, sizeof(ctx1));
 	spdk_io_device_register(&device2, create_cb_2, destroy_cb_2, sizeof(ctx2));
-	spdk_io_device_register(&device3, create_cb_null, NULL, 0);
 
 	g_create_cb_calls = 0;
 	ch1 = spdk_get_io_channel(&device1);