diff --git a/src/blackmisc/simulation/interpolationlogger.cpp b/src/blackmisc/simulation/interpolationlogger.cpp
index e2ffab342..796d8b099 100644
--- a/src/blackmisc/simulation/interpolationlogger.cpp
+++ b/src/blackmisc/simulation/interpolationlogger.cpp
@@ -429,6 +429,7 @@ namespace BlackMisc
                    QStringLiteral(" ") % cgAboveGround.valueRoundedWithUnit(CLengthUnit::ft(), 1) %
                    QStringLiteral(" | alt.cor.: ") % altCorrection %
                    QStringLiteral(" | #nw.sit.: ") % QString::number(noNetworkSituations) %
+                   QStringLiteral(" | #invalid: ") % QString::number(noInvalidSituations) %
                    (
                        withDeltaTimes ?
                        separator %
diff --git a/src/blackmisc/simulation/interpolationlogger.h b/src/blackmisc/simulation/interpolationlogger.h
index bb760803b..e41716aa3 100644
--- a/src/blackmisc/simulation/interpolationlogger.h
+++ b/src/blackmisc/simulation/interpolationlogger.h
@@ -39,6 +39,7 @@ namespace BlackMisc
             double deltaSampleTimesMs = -1; //!< delta time between samples (i.e. 2 situations)
             bool useParts = false;          //!< supporting aircraft parts
             int noNetworkSituations = 0;    //!< available network situations
+            int noInvalidSituations = 0;    //!< invalid situations, missing situations for timestampd
             QString elevationInfo;          //!< info about elevation retrieval
             QString altCorrection;          //!< info about altitude correction as CAircraftSituation::AltitudeCorrection
             Aviation::CCallsign callsign;   //!< current callsign