diff --git a/examples/ndn-grid.py b/examples/ndn-grid.py
index 5569b11..c13c405 100644
--- a/examples/ndn-grid.py
+++ b/examples/ndn-grid.py
@@ -51,7 +51,7 @@
 
 Config.SetDefault("ns3::PointToPointNetDevice::DataRate", StringValue("10Mbps"))
 Config.SetDefault("ns3::PointToPointChannel::Delay", StringValue("10ms"))
-Config.SetDefault("ns3::DropTailQueue::MaxPackets", StringValue("20"))
+Config::SetDefault("ns3::QueueBase::MaxPackets", UintegerValue(20))
 
 import sys; cmd = CommandLine(); cmd.Parse(sys.argv);