diff --git a/libsrc/common/_cwd.s b/libsrc/common/_cwd.s
index 19e1af703..a3ee362f6 100644
--- a/libsrc/common/_cwd.s
+++ b/libsrc/common/_cwd.s
@@ -8,23 +8,25 @@
 ;
 
        	.export		__cwd
+        .export         __cwd_buf_size
         .constructor    cwd_init
 
         .import         initcwd
 
         .include        "stdio.inc"
-
+                                      
+        __cwd_buf_size  = FILENAME_MAX
 
         cwd_init        := initcwd
 
 .bss
 
-__cwd:  .res	FILENAME_MAX
+__cwd:  .res	__cwd_buf_size
 
 
 ; NOTE: Some of the code working with directories is not able to handle
 ; strings longer than 255 chars, so don't make __cwd larger than 256 without
 ; checking the other sources.
 
-        .assert FILENAME_MAX < 256, error, "FILENAME_MAX must not be > 255"
+        .assert __cwd_buf_size < 256, error, "__cwd_buf_size must not be > 255"