Index: uspace/lib/libc/generic/vfs.c
===================================================================
--- uspace/lib/libc/generic/vfs.c	(revision 2db4ac8457acaa2a1655dc42d95e27e27dbdc03f)
+++ uspace/lib/libc/generic/vfs.c	(revision 9652bd59e77f347c04ec00c93fda8652cb52baa6)
@@ -166,5 +166,8 @@
 	async_serialize_end();
 	futex_up(&vfs_phone_futex);
-	return (ssize_t) IPC_GET_ARG1(answer);
+	if (rc == EOK)
+		return (ssize_t) IPC_GET_ARG1(answer);
+	else
+		return -1;
 }
 
@@ -196,5 +199,8 @@
 	async_serialize_end();
 	futex_up(&vfs_phone_futex);
-	return (ssize_t) IPC_GET_ARG1(answer);
+	if (rc == EOK)
+		return (ssize_t) IPC_GET_ARG1(answer);
+	else
+		return -1;
 }