diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index b9357440e95..91681265b1c 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -342,7 +342,9 @@ bool MarkBlockAsInFlight(NodeId nodeid, const uint256& hash, const CBlockIndex*
     // Short-circuit most stuff in case its from the same node
     std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash);
     if (itInFlight != mapBlocksInFlight.end() && itInFlight->second.first == nodeid) {
-        *pit = &itInFlight->second.second;
+        if (pit) {
+            *pit = &itInFlight->second.second;
+        }
         return false;
     }