diff --git a/src/compile.c b/src/compile.c
index a8e5e39..b659242 100644
--- a/src/compile.c
+++ b/src/compile.c
@@ -400,7 +400,7 @@ compile_assignable_var_path(
         ilist_put_insn(args.ilist, INSN_STRING);
         ilist_put_string(args.ilist, dot_rhs);
         ilist_put_insn(args.ilist, INSN_MATCHER_SET_VAL);
-        ilist_put_insn(args.ilist, index);
+        ilist_put_index(args.ilist, index);
         return true;
     case APFL_EXPR_ASSIGNABLE_VAR_OR_MEMBER_AT:
         TRY(compile_assignable_var_path(compiler, var_or_member->dot.lhs, args, path_len, varname));