diff --git a/ChangeLog b/ChangeLog
index 935dea5ed..48ae96468 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-07-12  Mike Kestner  <mkestner@novell.com>
+
+	* glib/GType.cs: fail gracefully for non-studly-case typename lookups.
+	[Fixes #515453]
+
 2009-07-12  Mike Kestner  <mkestner@novell.com>
 
 	* sample/Makefile.am: fix for cairo conflicts related to the switch to gmcs.
diff --git a/glib/GType.cs b/glib/GType.cs
index 94471e8aa..762b00639 100755
--- a/glib/GType.cs
+++ b/glib/GType.cs
@@ -162,7 +162,7 @@ namespace GLib {
 				}
 			}
 
-			throw new ArgumentException ("cname is not in NamespaceType format. GType.Register should be called directly for " + cname);
+			return null;
 		}
 
 		public static explicit operator Type (GType gtype)
@@ -182,6 +182,8 @@ namespace GLib {
 
 			string native_name = Marshaller.Utf8PtrToString (g_type_name (typeid));
 			string type_name = GetQualifiedName (native_name);
+			if (type_name == null)
+				return null;
 			Type result = null;
 			Assembly[] assemblies = (Assembly[]) AppDomain.CurrentDomain.GetAssemblies ().Clone ();
 			foreach (Assembly asm in assemblies) {