diff --git a/src/vim9compile.c b/src/vim9compile.c
index af11ba9..afc7885 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -2008,7 +2008,7 @@
 			    : isn->isn_arg.number != needed_list_len)
 		    {
 			semsg(_(e_expected_nr_items_but_got_nr),
-					 needed_list_len, isn->isn_arg.number);
+				    needed_list_len, (int)isn->isn_arg.number);
 			goto theend;
 		    }
 		}