Index: uspace/lib/posix/include/posix/stdio.h
===================================================================
--- uspace/lib/posix/include/posix/stdio.h	(revision e3c960e1bdab0baa0afb2fefa5847dedc0fac870)
+++ uspace/lib/posix/include/posix/stdio.h	(revision dc5a1f262fb49af9ac9f66e998d2fcbff5f0ab2a)
@@ -64,5 +64,9 @@
 #define EOF (-1)
 
+/** Size of buffers used in stdio header. */
 #define BUFSIZ  4096
+
+/** Maximum size in bytes of the longest filename. */
+#define FILENAME_MAX 4096
 
 typedef struct _IO_FILE FILE;