diff --git a/tests/unit-tests/model/ndn-old-content-store.t.cpp b/tests/unit-tests/model/ndn-old-content-store.t.cpp
index a2919f4..c2e9c43 100644
--- a/tests/unit-tests/model/ndn-old-content-store.t.cpp
+++ b/tests/unit-tests/model/ndn-old-content-store.t.cpp
@@ -29,7 +29,7 @@
 {
   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"));
 
   getStackHelper().SetOldContentStore("ns3::ndn::cs::Random", "MaxSize", "10");