diff --git a/sources/custom/Object.cs b/sources/custom/Object.cs
index 1339002b3c..a9ddaa682b 100644
--- a/sources/custom/Object.cs
+++ b/sources/custom/Object.cs
@@ -28,14 +28,12 @@ namespace Gst {
 		[DllImport ("libgobject-2.0-0.dll", CallingConvention = CallingConvention.Cdecl)]
 		static extern IntPtr g_object_class_find_property (IntPtr klass, IntPtr name);
 
-
 		bool PropertyExists (string name) {
 			if (PropertyNameCache.ContainsKey (name))
 				return PropertyNameCache [name];
 
-			var ptr = g_object_class_find_property (GType.GetClassPtr (), GLib.Marshaller.StringToPtrGStrdup (name));
+			var ptr = g_object_class_find_property (Marshal.ReadIntPtr (Handle), GLib.Marshaller.StringToPtrGStrdup (name));
 			var result = ptr != IntPtr.Zero;
-			GLib.Marshaller.Free (ptr);
 
 			// just cache the positive results because there might
 			// actually be new properties getting installed