Index: uspace/lib/usbhost/src/batch.c
===================================================================
--- uspace/lib/usbhost/src/batch.c	(revision aa81adc7bcff3b5af18aca49cf5866edf842f157)
+++ uspace/lib/usbhost/src/batch.c	(revision c3bc8a83d9f789070d9fc7d9b12e83b234dc77d2)
@@ -109,4 +109,5 @@
 	assert(instance);
 	assert(instance->ep);
+	assert(instance->next_step);
 	endpoint_release(instance->ep);
 	instance->next_step(instance);