diff --git a/spine-libgdx/spine-skeletonviewer/src/com/esotericsoftware/spine/SkeletonViewer.java b/spine-libgdx/spine-skeletonviewer/src/com/esotericsoftware/spine/SkeletonViewer.java
index 1bd2cfbbf..37a3f34d5 100644
--- a/spine-libgdx/spine-skeletonviewer/src/com/esotericsoftware/spine/SkeletonViewer.java
+++ b/spine-libgdx/spine-skeletonviewer/src/com/esotericsoftware/spine/SkeletonViewer.java
@@ -496,6 +496,8 @@ public class SkeletonViewer extends ApplicationAdapter {
 
 			alphaSlider.setValue(1);
 			alphaSlider.setDisabled(true);
+			
+			addCheckbox.setDisabled(true);
 
 			window.setMovable(false);
 			window.setResizable(false);