diff --git a/pygtk/gtk/gdkevent.override b/pygtk/gtk/gdkevent.override
index 3c0501d..131e2e1 100644
--- a/pygtk/gtk/gdkevent.override
+++ b/pygtk/gtk/gdkevent.override
@@ -354,8 +354,10 @@ _wrap_gdk_event_tp_setattr(PyObject *self, char *attr, PyObject *value)
 	    char *tmp;
 	    STRING_CHECK();
 	    tmp = PyString_AsString(value);
-	    strncpy((char *) &event->client.data, tmp,
-                    sizeof(event->client.data));
+			int len = sizeof(event->client.data.b);
+	    strncpy(event->client.data.b, tmp, len - 1);
+			if (strlen(tmp) > len)
+				event->client.data.b[len - 1] = '\0';
 	    return 0;
 	}
 	break;