diff --git a/src/blackmisc/simulation/interpolator.cpp b/src/blackmisc/simulation/interpolator.cpp
index b097a4c37..2e711f8fa 100644
--- a/src/blackmisc/simulation/interpolator.cpp
+++ b/src/blackmisc/simulation/interpolator.cpp
@@ -201,7 +201,7 @@ namespace BlackMisc
 
         template <typename Derived>
         CAircraftParts CInterpolator<Derived>::getInterpolatedParts(qint64 currentTimeMsSinceEpoch,
-                const CInterpolationAndRenderingSetup &setup, CPartsStatus &partsStatus, bool log)
+                const CInterpolationAndRenderingSetup &setup, CPartsStatus &partsStatus, bool log) const
         {
             Q_UNUSED(setup);
             partsStatus.reset();
@@ -268,7 +268,7 @@ namespace BlackMisc
         }
 
         template<typename Derived>
-        void CInterpolator<Derived>::logParts(qint64 timestamp, const CAircraftParts &parts, bool empty, bool log)
+        void CInterpolator<Derived>::logParts(qint64 timestamp, const CAircraftParts &parts, bool empty, bool log) const
         {
             if (!log || !m_logger) { return; }
             CInterpolationLogger::PartsLog logInfo;
diff --git a/src/blackmisc/simulation/interpolator.h b/src/blackmisc/simulation/interpolator.h
index 42184d422..95892edf4 100644
--- a/src/blackmisc/simulation/interpolator.h
+++ b/src/blackmisc/simulation/interpolator.h
@@ -50,7 +50,7 @@ namespace BlackMisc
 
             //! Parts before given offset time (aka pending parts)
             Aviation::CAircraftParts getInterpolatedParts(
-                qint64 currentTimeSinceEpoc, const CInterpolationAndRenderingSetup &setup, CPartsStatus &partsStatus, bool log = false);
+                qint64 currentTimeSinceEpoc, const CInterpolationAndRenderingSetup &setup, CPartsStatus &partsStatus, bool log = false) const;
 
             //! Add a new aircraft situation
             void addAircraftSituation(const Aviation::CAircraftSituation &situation);
@@ -101,7 +101,7 @@ namespace BlackMisc
             CInterpolationLogger *m_logger = nullptr;
 
             //! Log parts
-            void logParts(qint64 timestamp, const Aviation::CAircraftParts &parts, bool empty, bool log);
+            void logParts(qint64 timestamp, const Aviation::CAircraftParts &parts, bool empty, bool log) const;
 
             Derived *derived() { return static_cast<Derived *>(this); }
             const Derived *derived() const { return static_cast<const Derived *>(this); }
diff --git a/src/blackmisc/simulation/interpolatordummy.h b/src/blackmisc/simulation/interpolatordummy.h
index e44fc8945..d0689db19 100644
--- a/src/blackmisc/simulation/interpolatordummy.h
+++ b/src/blackmisc/simulation/interpolatordummy.h
@@ -42,7 +42,7 @@ namespace BlackMisc
 
             //! \copydoc CInterpolator::getInterpolatedParts
             BlackMisc::Aviation::CAircraftParts getInterpolatedParts(
-                qint64, const CInterpolationAndRenderingSetup &, CPartsStatus &, bool = false) { return {}; }
+                qint64, const CInterpolationAndRenderingSetup &, CPartsStatus &, bool = false) const { return {}; }
 
             //! \copydoc CInterpolator::addAircraftSituation
             void addAircraftSituation(const BlackMisc::Aviation::CAircraftSituation &) {}
diff --git a/src/blackmisc/simulation/interpolatormulti.cpp b/src/blackmisc/simulation/interpolatormulti.cpp
index ba601c42b..05d54bb3e 100644
--- a/src/blackmisc/simulation/interpolatormulti.cpp
+++ b/src/blackmisc/simulation/interpolatormulti.cpp
@@ -39,7 +39,7 @@ namespace BlackMisc
 
         CAircraftParts CInterpolatorMulti::getInterpolatedParts(
             qint64 currentTimeSinceEpoc, const CInterpolationAndRenderingSetup &setup,
-            CPartsStatus &partsStatus, bool log)
+            CPartsStatus &partsStatus, bool log) const
         {
             switch (m_mode)
             {
diff --git a/src/blackmisc/simulation/interpolatormulti.h b/src/blackmisc/simulation/interpolatormulti.h
index 9dd575278..3a4745bd6 100644
--- a/src/blackmisc/simulation/interpolatormulti.h
+++ b/src/blackmisc/simulation/interpolatormulti.h
@@ -40,7 +40,7 @@ namespace BlackMisc
             Aviation::CAircraftParts getInterpolatedParts(
                 qint64 currentTimeSinceEpoc,
                 const CInterpolationAndRenderingSetup &setup,
-                CPartsStatus &partsStatus, bool log = false);
+                CPartsStatus &partsStatus, bool log = false) const;
 
             //! \copydoc CInterpolator::addAircraftSituation
             void addAircraftSituation(const Aviation::CAircraftSituation &situation);