diff --git a/stdio.asm b/stdio.asm
index 1b36bf7..1f18719 100644
--- a/stdio.asm
+++ b/stdio.asm
@@ -3118,7 +3118,7 @@ f	equ	1	file pointer
 	
 lb1	creturn 4:f
 
-type	cstr	'w+b'
+type	cstr	'w+bx'
 	end
 
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