diff --git a/py/misc.h b/py/misc.h
index 97e16c2..044fef6 100644
--- a/py/misc.h
+++ b/py/misc.h
@@ -100,6 +100,7 @@
 bool unichar_islower(unichar c);
 unichar unichar_tolower(unichar c);
 unichar unichar_toupper(unichar c);
+#define unichar_charlen(s, bytelen) (bytelen)
 
 /** variable string *********************************************/