diff --git a/PartPreviewWindow/ViewGcodeWidget.cs b/PartPreviewWindow/ViewGcodeWidget.cs
index a6a8a3861..f6b5ccf9e 100644
--- a/PartPreviewWindow/ViewGcodeWidget.cs
+++ b/PartPreviewWindow/ViewGcodeWidget.cs
@@ -508,6 +508,11 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 
 		public override void OnClosed(EventArgs e)
 		{
+			if (gCodeRenderer != null)
+			{
+				gCodeRenderer.Dispose();
+			}
+
 			if (backgroundWorker != null)
 			{
 				backgroundWorker.CancelAsync();
diff --git a/Submodules/agg-sharp b/Submodules/agg-sharp
index 968ab38ab..e777fc325 160000
--- a/Submodules/agg-sharp
+++ b/Submodules/agg-sharp
@@ -1 +1 @@
-Subproject commit 968ab38ab62bb3ff58e99c404ee6a817f3c46907
+Subproject commit e777fc325ba5e1c11e232bcea7801c007746f82b