diff --git a/scanslicer/ui_builders.py b/scanslicer/ui_builders.py
index 576f8e7..ae60a76 100644
--- a/scanslicer/ui_builders.py
+++ b/scanslicer/ui_builders.py
@@ -6,3 +6,10 @@ from .ui_builders_shared import ScrollbarWheelOnlyScrollArea, icon_from_svg_data
 # ScanSlicerUiBuilderMixin: class definition for ScanSlicer behavior.
 class ScanSlicerUiBuilderMixin(ScanSlicerUiControlsMixin, ScanSlicerUiPreviewMixin):
     """Composed UI builder mixin split by panel responsibility."""
+
+
+__all__ = [
+    "ScanSlicerUiBuilderMixin",
+    "ScrollbarWheelOnlyScrollArea",
+    "icon_from_svg_data_url",
+]