diff --git a/src/Bonsai.Gui/CheckButtonBuilderBase.cs b/src/Bonsai.Gui/CheckButtonBuilderBase.cs
index b5e5d75..9df8a9b 100644
--- a/src/Bonsai.Gui/CheckButtonBuilderBase.cs
+++ b/src/Bonsai.Gui/CheckButtonBuilderBase.cs
@@ -7,7 +7,7 @@ namespace Bonsai.Gui
     /// <summary>
     /// Provides an abstract base class with common check button control functionality.
     /// </summary>
-    public class CheckButtonBuilderBase : ButtonBuilderBase<bool>
+    public abstract class CheckButtonBuilderBase : ButtonBuilderBase<bool>
     {
         internal readonly BehaviorSubject<bool> _Checked = new(false);