diff --git a/sys/sys/proc.h b/sys/sys/proc.h
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -430,7 +430,7 @@
 #define	TD_LOCKS_INC(td)	((td)->td_locks++)
 #define	TD_LOCKS_DEC(td) do {						\
 	KASSERT(SCHEDULER_STOPPED_TD(td) || (td)->td_locks > 0,		\
-	    ("thread %p owns no locks", (td)));				\
+	    ("Thread %p owns no locks", (td)));				\
 	(td)->td_locks--;						\
 } while (0)
 #else