diff --git a/src/test/ns3tcp/ns3tcp-loss-test-suite.cc b/src/test/ns3tcp/ns3tcp-loss-test-suite.cc
index 534c46b3e..ca3179319 100644
--- a/src/test/ns3tcp/ns3tcp-loss-test-suite.cc
+++ b/src/test/ns3tcp/ns3tcp-loss-test-suite.cc
@@ -132,7 +132,9 @@ Ns3TcpLossTestCase::DoSetup (void)
   else
     {
       m_pcapFile.Open (m_pcapFilename, std::ios::in|std::ios::binary);
-      NS_ABORT_MSG_UNLESS (m_pcapFile.GetDataLinkType () == PCAP_LINK_TYPE, "Wrong response vectors in directory");
+      NS_ABORT_MSG_UNLESS (m_pcapFile.GetDataLinkType () == PCAP_LINK_TYPE,
+                           "Wrong response vectors in directory: opening " <<
+                           m_pcapFilename);
     }
 }
 
diff --git a/src/test/ns3tcp/ns3tcp-state-test-suite.cc b/src/test/ns3tcp/ns3tcp-state-test-suite.cc
index 8b8c9c860..e4dad603d 100644
--- a/src/test/ns3tcp/ns3tcp-state-test-suite.cc
+++ b/src/test/ns3tcp/ns3tcp-state-test-suite.cc
@@ -129,7 +129,9 @@ Ns3TcpStateTestCase::DoSetup (void)
   else
     {
       m_pcapFile.Open (m_pcapFilename, std::ios::in|std::ios::binary);
-      NS_ABORT_MSG_UNLESS (m_pcapFile.GetDataLinkType () == PCAP_LINK_TYPE, "Wrong response vectors in directory");
+      NS_ABORT_MSG_UNLESS (m_pcapFile.GetDataLinkType () == PCAP_LINK_TYPE,
+                           "Wrong response vectors in directory: opening " <<
+                           m_pcapFilename);
     }
 }