Index: kernel/generic/include/ipc/ipc.h
===================================================================
--- kernel/generic/include/ipc/ipc.h	(revision 6c34f587dc553bfe599e1e96d19701a9d33eddf4)
+++ kernel/generic/include/ipc/ipc.h	(revision ecd1a0aa0746649b810764037fa03dca950f5122)
@@ -113,10 +113,4 @@
 	struct task *sender;
 	
-	/*
-	 * The caller box is different from sender->answerbox
-	 * for synchronous calls.
-	 */
-	answerbox_t *callerbox;
-	
 	/** Private data to internal IPC. */
 	sysarg_t priv;