diff --git a/src/UI/Timeline/NewTileMapLayerDialog.gd b/src/UI/Timeline/NewTileMapLayerDialog.gd
index cdb1f71fc..c6b790e7c 100644
--- a/src/UI/Timeline/NewTileMapLayerDialog.gd
+++ b/src/UI/Timeline/NewTileMapLayerDialog.gd
@@ -37,3 +37,9 @@ func _on_about_to_popup() -> void:
 		if not tileset.name.is_empty():
 			item_string += ": " + tileset.name
 		tileset_option_button.add_item(tr("Tileset" + item_string))
+	_on_tileset_option_button_item_selected(tileset_option_button.selected)
+
+
+func _on_tileset_option_button_item_selected(index: int) -> void:
+	tileset_name_line_edit.editable = index == 0
+	tile_size_slider.editable = tileset_name_line_edit.editable
diff --git a/src/UI/Timeline/NewTileMapLayerDialog.tscn b/src/UI/Timeline/NewTileMapLayerDialog.tscn
index 46fb9dde5..2d20c8d36 100644
--- a/src/UI/Timeline/NewTileMapLayerDialog.tscn
+++ b/src/UI/Timeline/NewTileMapLayerDialog.tscn
@@ -67,3 +67,4 @@ suffix_y = "px"
 [connection signal="about_to_popup" from="." to="." method="_on_about_to_popup"]
 [connection signal="confirmed" from="." to="." method="_on_confirmed"]
 [connection signal="visibility_changed" from="." to="." method="_on_visibility_changed"]
+[connection signal="item_selected" from="GridContainer/TilesetOptionButton" to="." method="_on_tileset_option_button_item_selected"]