diff --git a/apps/netmonitor/java/src/net/i2p/netmonitor/PeerSummaryReader.java b/apps/netmonitor/java/src/net/i2p/netmonitor/PeerSummaryReader.java
index d1cf2042a77c614ee007d9bca966bcf18778ceee..1a132cf911b08c5df3c0b73f3d8b9308c6f1cdd0 100644
--- a/apps/netmonitor/java/src/net/i2p/netmonitor/PeerSummaryReader.java
+++ b/apps/netmonitor/java/src/net/i2p/netmonitor/PeerSummaryReader.java
@@ -84,6 +84,8 @@ class PeerSummaryReader {
             }
         }
         
+        if (summary == null)
+            return;
         summary.coallesceData(monitor.getSummaryDurationHours() * 60*60*1000);
         monitor.addSummary(summary);
     }