diff --git a/asminc/stdio.inc b/asminc/stdio.inc
index 6eb458b62..426389de3 100644
--- a/asminc/stdio.inc
+++ b/asminc/stdio.inc
@@ -46,7 +46,7 @@ FILENAME_MAX    = 64+1
 .elseif .defined(__ATARI__)
 FILENAME_MAX    = 63+1
 .elseif .defined(__CBM__)
-FILENAME_MAX    = 256+1
+FILENAME_MAX    = 255
 .elseif .defined(__LUNIX__)
 FILENAME_MAX    = 80+1
 .elseif .defined(__TELESTRAT__)
diff --git a/include/limits.h b/include/limits.h
index 532f5104a..531c6bef2 100644
--- a/include/limits.h
+++ b/include/limits.h
@@ -69,7 +69,7 @@
 #elif defined(__ATARI__)
 #  define PATH_MAX      (63+1)
 #elif defined(__CBM__)
-#  define PATH_MAX      (256+1)
+#  define PATH_MAX      (255)  /* should be 256+1, see libsrc/common/_cmd.s why it's not */
 #elif defined(__LUNIX__)
 #  define PATH_MAX      (80+1)
 #elif defined(__TELESTRAT__)