diff --git a/shell/math.h b/shell/math.h
index e34b65d..2dcab13 100644
--- a/shell/math.h
+++ b/shell/math.h
@@ -95,7 +95,7 @@
 //typedef const char* FAST_FUNC (*arith_var_endofname_t)(const char *name);
 
 typedef struct arith_state_t {
-	int                   errcode;
+	const char           *errmsg;
 	arith_var_lookup_t    lookupvar;
 	arith_var_set_t       setvar;
 //	arith_var_endofname_t endofname;