diff --git a/SpriteLibrary/SpriteEntryForm.cs b/SpriteLibrary/SpriteEntryForm.cs
index f0b1037..ce8c60d 100644
--- a/SpriteLibrary/SpriteEntryForm.cs
+++ b/SpriteLibrary/SpriteEntryForm.cs
@@ -515,7 +515,11 @@ namespace SpriteLibrary
 
         private void WeHaveNewItem()
         {
-            if (PreviewSprite != null) PreviewSprite.Destroy();
+            if (PreviewSprite != null)
+            {
+                PreviewSprite.Destroy();
+                PreviewSprite = null;
+            }
             if (CurrentSIIndex >= 0 && CurrentSIIndex < SpriteInformation.Count)
                 TempInformation.CopyFrom(SpriteInformation[CurrentSIIndex]);
             else
@@ -626,7 +630,7 @@ namespace SpriteLibrary
 
         private void btnPreviewAnimBack_Click(object sender, EventArgs e)
         {
-            if (PreviewSprite != null)
+            if (PreviewSprite != null && !PreviewSprite.Destroying)
             {
                 int Animations = PreviewSprite.AnimationCount;
                 int NextAnim = PreviewSprite.AnimationIndex - 1;