diff --git a/Source/Libs/GtkSharp/CellRenderer.GetSize.cs b/Source/Libs/GtkSharp/CellRenderer.GetSize.cs
index 41145e44a..d499ae5dd 100644
--- a/Source/Libs/GtkSharp/CellRenderer.GetSize.cs
+++ b/Source/Libs/GtkSharp/CellRenderer.GetSize.cs
@@ -127,6 +127,8 @@ namespace Gtk
 			}
 
 			var obj = TryGetObject (cell);
+			if (obj == default)
+				return;
 			var parent = obj.NativeType;
 			while ((parent = parent.GetBaseType ()) != GLib.GType.None) {
 				
diff --git a/Source/Libs/GtkSharp/Container.Forall.cs b/Source/Libs/GtkSharp/Container.Forall.cs
index 788a0dd5f..a6ade093d 100644
--- a/Source/Libs/GtkSharp/Container.Forall.cs
+++ b/Source/Libs/GtkSharp/Container.Forall.cs
@@ -137,6 +137,9 @@ namespace Gtk
 				return;
 
 			var obj = TryGetObject(container);
+			if (obj == default)
+				return;
+			
 			var parent = obj.NativeType;
 			while ((parent = parent.GetBaseType()) != GLib.GType.None) {
 				if (parent.ToString().StartsWith("__gtksharp_")) {