1 files changed, 4 insertions, 0 deletions
diff --git a/source/luametatex/source/lua/lmtfontlib.c b/source/luametatex/source/lua/lmtfontlib.c
index 9850d59e7..f743f960e 100644
--- a/source/luametatex/source/lua/lmtfontlib.c
+++ b/source/luametatex/source/lua/lmtfontlib.c
@@ -332,6 +332,10 @@ static void fontlib_aux_font_char_from_lua(lua_State *L, halfword f, int i, int
             if (target) {
                 set_charinfo_tag(co, extend_last_tag);
             } 
+            set_boolean_field_by_index(target, keepbase, 0);
+            if (target) {
+                set_charinfo_tag(co, keep_base_tag);
+            } 
             lua_push_key(parts);
             if (lua_rawget(L, -2) == LUA_TTABLE) {
                 set_charinfo_tag(co, extensible_tag);