diff --git a/glib/Opaque.cs b/glib/Opaque.cs
index 5eca7fdd3..955285f6a 100644
--- a/glib/Opaque.cs
+++ b/glib/Opaque.cs
@@ -67,6 +67,10 @@ namespace GLib {
 				return _obj;
 			}
 			set {
+				if (_obj == value) {
+					return;
+				}
+
 				if (_obj != IntPtr.Zero) {
 					Unref (_obj);
 					if (owned)