diff --git a/libasn1compiler/asn1c_constraint.c b/libasn1compiler/asn1c_constraint.c
index 672390e..9a37fd2 100644
--- a/libasn1compiler/asn1c_constraint.c
+++ b/libasn1compiler/asn1c_constraint.c
@@ -570,7 +570,7 @@
 static asn1p_expr_type_e
 _find_terminal_type(arg_t *arg) {
 	asn1p_expr_t *expr;
-	expr = asn1f_find_terminal_type_ex(arg->asn, arg->mod, arg->expr, NULL);
+	expr = asn1f_find_terminal_type_ex(arg->asn, arg->mod, arg->expr);
 	if(expr) return expr->expr_type;
 	return A1TC_INVALID;
 }