diff --git a/src/runtime/Files.Mod b/src/runtime/Files.Mod
index eb369b3c..c06d2f2b 100644
--- a/src/runtime/Files.Mod
+++ b/src/runtime/Files.Mod
@@ -29,7 +29,7 @@ MODULE Files;  (* J. Templ 1.12. 89/12.4.95 Oberon files mapped onto Unix files
                       name *)
 
   TYPE
-    FileName = ARRAY 101 OF CHAR;
+    FileName = ARRAY 256 OF CHAR;
     File*    = POINTER TO FileDesc;
     Buffer   = POINTER TO BufDesc;