Index: kernel/generic/src/ipc/ipc.c
===================================================================
--- kernel/generic/src/ipc/ipc.c	(revision 5c0889751538969abfb6f515b8ac7a0770490947)
+++ kernel/generic/src/ipc/ipc.c	(revision 41a7f624830c173ff6e5ed22c0abc99dbc08751a)
@@ -702,10 +702,10 @@
 	for (i = 0; i < IPC_MAX_PHONES; i++) {
 		if (SYNCH_FAILED(mutex_trylock(&task->phones[i].lock))) {
-			printf("%d: mutex busy\n", i);
+			printf("%zu: mutex busy\n", i);
 			continue;
 		}
 		
 		if (task->phones[i].state != IPC_PHONE_FREE) {
-			printf("%" PRIs ": ", i);
+			printf("%zu: ", i);
 			
 			switch (task->phones[i].state) {