diff --git a/src/blackmisc/simulation/settings/xswiftbussettingsqtfree.cpp b/src/blackmisc/simulation/settings/xswiftbussettingsqtfree.cpp
index 507ef7820..c0263bcbf 100644
--- a/src/blackmisc/simulation/settings/xswiftbussettingsqtfree.cpp
+++ b/src/blackmisc/simulation/settings/xswiftbussettingsqtfree.cpp
@@ -53,6 +53,27 @@ namespace BlackMisc
                 this->parseXSwiftBusString(json);
             }
 
+            bool CXSwiftBusSettingsQtFree::setMaxPlanes(int planes)
+            {
+                if (planes == m_maxPlanes) { return false; }
+                m_maxPlanes = planes;
+                return true;
+            }
+
+            bool CXSwiftBusSettingsQtFree::setFollowAircraftDistanceM(int meters)
+            {
+                if (meters == m_followAircraftDistanceM) { return false; }
+                m_followAircraftDistanceM = meters;
+                return true;
+            }
+
+            bool CXSwiftBusSettingsQtFree::setMaxDrawDistanceNM(double nauticalMiles)
+            {
+                if (isFuzzyEqual(nauticalMiles, m_maxDrawDistanceNM)) { return false; }
+                m_maxDrawDistanceNM = nauticalMiles;
+                return true;
+            }
+
             bool CXSwiftBusSettingsQtFree::parseXSwiftBusString(const std::string &json)
             {
                 if (json.empty()) { return false; }
diff --git a/src/blackmisc/simulation/settings/xswiftbussettingsqtfree.h b/src/blackmisc/simulation/settings/xswiftbussettingsqtfree.h
index 40fd63edf..c58b77f4a 100644
--- a/src/blackmisc/simulation/settings/xswiftbussettingsqtfree.h
+++ b/src/blackmisc/simulation/settings/xswiftbussettingsqtfree.h
@@ -46,13 +46,13 @@ namespace BlackMisc
                 bool isDrawingLabels() const { return m_drawingLabels; }
 
                 //! Set the maximum number of aircraft.
-                void setMaxPlanes(int planes) { m_maxPlanes = planes; }
+                bool setMaxPlanes(int planes);
 
                 //! Get the maximum number of aircraft.
                 int getMaxPlanes() const { return m_maxPlanes; }
 
                 //! Set follow aircraft distance
-                void setFollowAircraftDistanceM(int meters) { m_followAircraftDistanceM = meters; }
+                bool setFollowAircraftDistanceM(int meters);
 
                 //! Get follow aircraft distance
                 int getFollowAircraftDistanceM() const { return m_followAircraftDistanceM; }
@@ -61,7 +61,7 @@ namespace BlackMisc
                 double getMaxDrawDistanceNM() const { return m_maxDrawDistanceNM; }
 
                 //! Set the maximum distance at which to draw aircraft (nautical miles).
-                void setMaxDrawDistanceNM(double nauticalMiles) { m_maxDrawDistanceNM = nauticalMiles; }
+                bool setMaxDrawDistanceNM(double nauticalMiles);
 
                 //! Load and parse config file
                 bool parseXSwiftBusString(const std::string &json);