diff --git a/examples/ndn-grid.py b/examples/ndn-grid.py
index c13c405..b7884e7 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::QueueBase::MaxPackets", UintegerValue(20))
+Config::SetDefault("ns3::QueueBase::MaxSize", StringValue("20p"))
 
 import sys; cmd = CommandLine(); cmd.Parse(sys.argv);