diff --git a/src/blackmisc/simulation/simulationenvironmentprovider.cpp b/src/blackmisc/simulation/simulationenvironmentprovider.cpp
index c886baef8..33e24f4b8 100644
--- a/src/blackmisc/simulation/simulationenvironmentprovider.cpp
+++ b/src/blackmisc/simulation/simulationenvironmentprovider.cpp
@@ -213,6 +213,7 @@ namespace BlackMisc
         {
             if (callsign.isEmpty()) { return false; }
             QReadLocker l(&m_lockCG);
+            if (!m_cgsPerCallsign.contains(callsign)) { return false; }
             return m_cgsPerCallsign[callsign] == cg;
         }