Index: uspace/srv/audio/hound/hound.c
===================================================================
--- uspace/srv/audio/hound/hound.c	(revision 9c3038d4dbd35b5a7471af62fa120a4a1bcc39a8)
+++ uspace/srv/audio/hound/hound.c	(revision 7be8d4d5475f5cc134500fe6ac5b52fb26fe5165)
@@ -146,4 +146,5 @@
 static void hound_remove_source_internal(hound_t *hound, audio_source_t *source)
 {
+	assert(fibril_mutex_is_locked(&hound->list_guard));
 	log_verbose("Removing source '%s'.", source->name);
 	if (!list_empty(&source->connections))