Index: uspace/lib/c/include/io/con_srv.h
===================================================================
--- uspace/lib/c/include/io/con_srv.h	(revision c19a5a59bb6be5cf8da4e0c9a6a35d207103bc14)
+++ uspace/lib/c/include/io/con_srv.h	(revision 86bbca413cd4472a041d8633c827dff484ee576a)
@@ -69,6 +69,6 @@
 	int (*open)(con_srvs_t *, con_srv_t *);
 	int (*close)(con_srv_t *);
-	int (*read)(con_srv_t *, void *, size_t);
-	int (*write)(con_srv_t *, void *, size_t);
+	int (*read)(con_srv_t *, void *, size_t, size_t *);
+	int (*write)(con_srv_t *, void *, size_t, size_t *);
 	void (*sync)(con_srv_t *);
 	void (*clear)(con_srv_t *);