diff --git a/src/compiler/sema_const.c b/src/compiler/sema_const.c
index ee2b0cae1..bdbc9d798 100644
--- a/src/compiler/sema_const.c
+++ b/src/compiler/sema_const.c
@@ -146,10 +146,10 @@ static bool sema_concat_bytes_and_other(SemaContext *context, Expr *expr, Expr *
 	ArraySize len = left->const_expr.bytes.len;
 	bool is_bytes = left->const_expr.const_kind == CONST_BYTES;
 	Type *indexed = type_get_indexed_type(left->type);
-	bool const_cast = sema_cast_const(right);
-	ASSERT(const_cast);
 	const char *left_bytes = left->const_expr.bytes.ptr;
-	RETRY:;
+RETRY:;
+	(void)sema_cast_const(right);
+	ASSERT(expr_is_const(right));
 	switch (right->const_expr.const_kind)
 	{
 		case CONST_INTEGER: