diff --git a/src/blackcore/webdataservices.cpp b/src/blackcore/webdataservices.cpp
index 0c7f8d6d1..f9915e479 100644
--- a/src/blackcore/webdataservices.cpp
+++ b/src/blackcore/webdataservices.cpp
@@ -523,7 +523,7 @@ namespace BlackCore
         return this->getInfoObjectCount(entity, m_sharedInfoDataReader);
     }
 
-    QString CWebDataServices::getDbReadersLog(const QString separator) const
+    QString CWebDataServices::getDbReadersLog(const QString &separator) const
     {
         QStringList report;
         if (m_dbInfoDataReader)     { report << m_dbInfoDataReader->getName() + ": " + m_dbInfoDataReader->getReadLog().getSummary(); }
@@ -536,7 +536,7 @@ namespace BlackCore
         return report.join(separator);
     }
 
-    QString CWebDataServices::getReadersLog(const QString separator) const
+    QString CWebDataServices::getReadersLog(const QString &separator) const
     {
         const QString db = this->getDbReadersLog(separator);
         QStringList report;
diff --git a/src/blackcore/webdataservices.h b/src/blackcore/webdataservices.h
index 9366d3d06..e628de58c 100644
--- a/src/blackcore/webdataservices.h
+++ b/src/blackcore/webdataservices.h
@@ -445,10 +445,10 @@ namespace BlackCore
         int getSharedInfoObjectCount(BlackMisc::Network::CEntityFlags::Entity entity) const;
 
         //! For all available DB readers the log info is generated
-        QString getDbReadersLog(const QString separator = "\n") const;
+        QString getDbReadersLog(const QString &separator = "\n") const;
 
         //! For all available readers the log info is generated
-        QString getReadersLog(const QString separator = "\n") const;
+        QString getReadersLog(const QString &separator = "\n") const;
 
         //! Has already successfully connect swift DB?
         bool hasSuccesfullyConnectedSwiftDb() const;
diff --git a/src/blackgui/components/dbstashcomponent.cpp b/src/blackgui/components/dbstashcomponent.cpp
index f9df172ad..90db669fe 100644
--- a/src/blackgui/components/dbstashcomponent.cpp
+++ b/src/blackgui/components/dbstashcomponent.cpp
@@ -142,13 +142,13 @@ namespace BlackGui
             ui->tvp_StashAircraftModels->updateContainerMaybeAsync(models);
         }
 
-        int CDbStashComponent::unstashModels(QSet<int> keys)
+        int CDbStashComponent::unstashModels(const QSet<int> &keys)
         {
             if (keys.isEmpty()) { return 0; }
             return ui->tvp_StashAircraftModels->removeDbKeys(keys);
         }
 
-        int CDbStashComponent::unstashModels(QStringList modelStrings)
+        int CDbStashComponent::unstashModels(const QStringList &modelStrings)
         {
             if (modelStrings.isEmpty()) { return 0; }
             return ui->tvp_StashAircraftModels->removeModelsWithModelString(modelStrings);
diff --git a/src/blackgui/components/dbstashcomponent.h b/src/blackgui/components/dbstashcomponent.h
index 3ec771743..308716faa 100644
--- a/src/blackgui/components/dbstashcomponent.h
+++ b/src/blackgui/components/dbstashcomponent.h
@@ -74,10 +74,10 @@ namespace BlackGui
             BlackMisc::CStatusMessage validateStashModel(const BlackMisc::Simulation::CAircraftModel &model, bool allowReplace) const;
 
             //! Unstash given models with keys
-            int unstashModels(QSet<int> keys);
+            int unstashModels(const QSet<int> &keys);
 
             //! Unstash given models by model string
-            int unstashModels(QStringList modelStrings);
+            int unstashModels(const QStringList &modelStrings);
 
             //! Unstash given models
             int unstashModels(const BlackMisc::Simulation::CAircraftModelList &models);
diff --git a/src/blackgui/components/mappingcomponent.cpp b/src/blackgui/components/mappingcomponent.cpp
index d8e9084c4..0ddef7590 100644
--- a/src/blackgui/components/mappingcomponent.cpp
+++ b/src/blackgui/components/mappingcomponent.cpp
@@ -179,7 +179,7 @@ namespace BlackGui
             ui->tw_SpecializedViews->setCurrentIndex(tabIndex);
         }
 
-        CAircraftModelList CMappingComponent::findModelsStartingWith(const QString modelName, Qt::CaseSensitivity cs)
+        CAircraftModelList CMappingComponent::findModelsStartingWith(const QString &modelName, Qt::CaseSensitivity cs)
         {
             Q_ASSERT(ui->tvp_AircraftModels);
             return ui->tvp_AircraftModels->container().findModelsStartingWith(modelName, cs);
diff --git a/src/blackgui/components/mappingcomponent.h b/src/blackgui/components/mappingcomponent.h
index 3a2a6cc84..b2ce68e44 100644
--- a/src/blackgui/components/mappingcomponent.h
+++ b/src/blackgui/components/mappingcomponent.h
@@ -84,7 +84,7 @@ namespace BlackGui
             void setTab(TabWidget tab);
 
             //! Find models starting with
-            BlackMisc::Simulation::CAircraftModelList findModelsStartingWith(const QString modelName, Qt::CaseSensitivity cs);
+            BlackMisc::Simulation::CAircraftModelList findModelsStartingWith(const QString &modelName, Qt::CaseSensitivity cs);
 
         signals:
             //! Request a text message
diff --git a/src/blackgui/components/textmessagecomponent.cpp b/src/blackgui/components/textmessagecomponent.cpp
index 8b363a4f5..982e5b457 100644
--- a/src/blackgui/components/textmessagecomponent.cpp
+++ b/src/blackgui/components/textmessagecomponent.cpp
@@ -293,7 +293,7 @@ namespace BlackGui
                    styleSheet;
         }
 
-        bool CTextMessageComponent::isCorrespondingTextMessageTabSelected(CTextMessage textMessage) const
+        bool CTextMessageComponent::isCorrespondingTextMessageTabSelected(const CTextMessage &textMessage) const
         {
             if (!this->isVisibleWidgetHack()) { return false; }
             if (!textMessage.hasValidRecipient()) { return false; }
diff --git a/src/blackgui/components/textmessagecomponent.h b/src/blackgui/components/textmessagecomponent.h
index f377f884b..3f383c3c2 100644
--- a/src/blackgui/components/textmessagecomponent.h
+++ b/src/blackgui/components/textmessagecomponent.h
@@ -100,7 +100,7 @@ namespace BlackGui
             void displayInInfoWindow(const BlackMisc::CVariant &message, int displayDurationMs) const;
 
             //! Command line was entered
-            void commandEntered(const QString commandLine, const BlackMisc::CIdentifier &originator);
+            void commandEntered(const QString &commandLine, const BlackMisc::CIdentifier &originator);
 
         private:
             QScopedPointer<Ui::CTextMessageComponent> ui;
@@ -137,7 +137,7 @@ namespace BlackGui
             BlackMisc::Simulation::CSimulatedAircraft getOwnAircraft() const;
 
             //! For this text message's recepient, is the current tab selected?
-            bool isCorrespondingTextMessageTabSelected(BlackMisc::Network::CTextMessage textMessage) const;
+            bool isCorrespondingTextMessageTabSelected(const BlackMisc::Network::CTextMessage &textMessage) const;
 
             //! Network connected?
             bool isNetworkConnected() const;
diff --git a/src/blackgui/editors/validationindicator.cpp b/src/blackgui/editors/validationindicator.cpp
index 9897dc7da..91da44ae4 100644
--- a/src/blackgui/editors/validationindicator.cpp
+++ b/src/blackgui/editors/validationindicator.cpp
@@ -103,7 +103,7 @@ namespace BlackGui
             Q_UNUSED(paintEvent);
         }
 
-        void CValidationIndicator::setBackgroundColor(const QString colorName)
+        void CValidationIndicator::setBackgroundColor(const QString &colorName)
         {
             if (colorName.isEmpty())
             {
diff --git a/src/blackgui/editors/validationindicator.h b/src/blackgui/editors/validationindicator.h
index 483a667d9..402dcad6d 100644
--- a/src/blackgui/editors/validationindicator.h
+++ b/src/blackgui/editors/validationindicator.h
@@ -72,7 +72,7 @@ namespace BlackGui
             QScopedPointer<Ui::CValidationIndicator> ui;
 
             //! Set background color
-            void setBackgroundColor(const QString colorName);
+            void setBackgroundColor(const QString &colorName);
 
             QTimer m_resetTimer; //!< reset to neutral
             QString m_originalStyleSheet; //!< stored, to be able to reset
diff --git a/src/blackgui/models/columnformatters.h b/src/blackgui/models/columnformatters.h
index 960c0cfb7..cb597f9a2 100644
--- a/src/blackgui/models/columnformatters.h
+++ b/src/blackgui/models/columnformatters.h
@@ -259,7 +259,7 @@ namespace BlackGui
         {
         public:
             //! Constructor
-            CValueObjectFormatter(int alignment = alignDefault(), bool i18n = true, QList<int> supportedRoles = roleDisplay()) : CDefaultFormatter(alignment, i18n, supportedRoles) {}
+            CValueObjectFormatter(int alignment = alignDefault(), bool i18n = true, const QList<int> &supportedRoles = roleDisplay()) : CDefaultFormatter(alignment, i18n, supportedRoles) {}
 
             //! \copydoc CDefaultFormatter::displayRole
             virtual BlackMisc::CVariant displayRole(const BlackMisc::CVariant &valueObject) const override;
@@ -344,7 +344,7 @@ namespace BlackGui
         {
         public:
             //! Constructor
-            CPhysiqalQuantiyFormatter(MU unit = MU::defaultUnit(), int digits = 2, int alignment = alignRightVCenter(), bool withUnit = true, bool i18n = true, QList<int> supportedRoles = roleDisplay()) : CValueObjectFormatter(alignment, i18n, supportedRoles), m_unit(unit), m_digits(digits), m_withUnit(withUnit) {}
+            CPhysiqalQuantiyFormatter(MU unit = MU::defaultUnit(), int digits = 2, int alignment = alignRightVCenter(), bool withUnit = true, bool i18n = true, const QList<int> &supportedRoles = roleDisplay()) : CValueObjectFormatter(alignment, i18n, supportedRoles), m_unit(unit), m_digits(digits), m_withUnit(withUnit) {}
 
             //! \copydoc BlackGui::Models::CDefaultFormatter::displayRole
             virtual BlackMisc::CVariant displayRole(const BlackMisc::CVariant &physicalQuantity) const override
diff --git a/src/blackgui/textmessagetextedit.cpp b/src/blackgui/textmessagetextedit.cpp
index 226528495..87f62825d 100644
--- a/src/blackgui/textmessagetextedit.cpp
+++ b/src/blackgui/textmessagetextedit.cpp
@@ -101,7 +101,7 @@ namespace BlackGui
     {
         if (messages.isEmpty()) { return ""; }
         QString html("<table>");
-        for (CTextMessage msg : messages)
+        for (const CTextMessage &msg : messages)
         {
             html += toHtml(msg, withFrom, withTo);
         }
diff --git a/src/blackinput/win/joystickwindows.cpp b/src/blackinput/win/joystickwindows.cpp
index 574bd4860..9ec6c6f20 100644
--- a/src/blackinput/win/joystickwindows.cpp
+++ b/src/blackinput/win/joystickwindows.cpp
@@ -119,7 +119,7 @@ namespace BlackInput
             }
         }
 
-        for (CJoystickDeviceInput input : m_joystickDeviceInputs)
+        for (const CJoystickDeviceInput &input : m_joystickDeviceInputs)
         {
             const qint32 buttonIndex = input.m_offset - DIJOFS_BUTTON0;
             bool isPressed = state.rgbButtons[buttonIndex] & 0x80;
diff --git a/src/blackmisc/applicationinfo.cpp b/src/blackmisc/applicationinfo.cpp
index 875999417..a54906515 100644
--- a/src/blackmisc/applicationinfo.cpp
+++ b/src/blackmisc/applicationinfo.cpp
@@ -83,7 +83,7 @@ namespace BlackMisc
         return this->getApplication() == Unknown && m_exePath.isNull();
     }
 
-    QString CApplicationInfo::asOtherSwiftVersionString(const QString separator) const
+    QString CApplicationInfo::asOtherSwiftVersionString(const QString &separator) const
     {
         return QStringLiteral("Version; ")  % this->getVersionString() % QStringLiteral(" os: ") % this->getPlatform() % separator %
                QStringLiteral("exe.path: ") % this->getExecutablePath() % separator %
diff --git a/src/blackmisc/applicationinfo.h b/src/blackmisc/applicationinfo.h
index 5be428ded..175f26470 100644
--- a/src/blackmisc/applicationinfo.h
+++ b/src/blackmisc/applicationinfo.h
@@ -129,7 +129,7 @@ namespace BlackMisc
         bool isNull() const;
 
         //! Formatted info
-        QString asOtherSwiftVersionString(const QString separator = " | ") const;
+        QString asOtherSwiftVersionString(const QString &separator = " | ") const;
 
         //! \copydoc BlackMisc::Mixin::String::toQString
         QString convertToQString(bool i18n = false) const;
diff --git a/src/blackmisc/dbusserver.cpp b/src/blackmisc/dbusserver.cpp
index 1d3bd3e5d..41ac2f574 100644
--- a/src/blackmisc/dbusserver.cpp
+++ b/src/blackmisc/dbusserver.cpp
@@ -110,13 +110,13 @@ namespace BlackMisc
         return connection.name().contains(p2pConnectionName());
     }
 
-    bool CDBusServer::dBusAddressToHostAndPort(QString address, QString &host, int &port)
+    bool CDBusServer::dBusAddressToHostAndPort(const QString &address, QString &host, int &port)
     {
-        address = address.trimmed().toLower().replace(' ', "");
-        if (address.contains("host=") || address.contains("port="))
+        const QString canonicalAddress = address.trimmed().toLower().replace(' ', "");
+        if (canonicalAddress.contains("host=") || canonicalAddress.contains("port="))
         {
             // "tcp:host=foo.com,port=123"
-            const QStringList parts(address.split(','));
+            const QStringList parts(canonicalAddress.split(','));
             for (const QString &part : parts)
             {
                 // "host=" or "tcp:host="
@@ -145,7 +145,7 @@ namespace BlackMisc
         }
     }
 
-    bool CDBusServer::dBusAddressToHostAndPort(QString dbusAddress, QString &o_host, QString &o_port)
+    bool CDBusServer::dBusAddressToHostAndPort(const QString &dbusAddress, QString &o_host, QString &o_port)
     {
         int port;
         const bool s = dBusAddressToHostAndPort(dbusAddress, o_host, port);
diff --git a/src/blackmisc/dbusserver.h b/src/blackmisc/dbusserver.h
index 2ad1cddeb..3fa20ad74 100644
--- a/src/blackmisc/dbusserver.h
+++ b/src/blackmisc/dbusserver.h
@@ -126,10 +126,10 @@ namespace BlackMisc
         static bool isP2PConnection(const QDBusConnection &connection);
 
         //! Extract host and port from a DBus address
-        static bool dBusAddressToHostAndPort(QString dbusAddress, QString &o_host, int &o_port);
+        static bool dBusAddressToHostAndPort(const QString &dbusAddress, QString &o_host, int &o_port);
 
         //! Extract host and port from a DBus address
-        static bool dBusAddressToHostAndPort(QString dbusAddress, QString &o_host, QString &o_port);
+        static bool dBusAddressToHostAndPort(const QString &dbusAddress, QString &o_host, QString &o_port);
 
         //! Is the given connection one of the default connections?
         static bool isQtDefaultConnection(const QDBusConnection &connection);
diff --git a/src/blackmisc/thirdparty/simplecrypt.cpp b/src/blackmisc/thirdparty/simplecrypt.cpp
index a7af37cae..0dd666e64 100644
--- a/src/blackmisc/thirdparty/simplecrypt.cpp
+++ b/src/blackmisc/thirdparty/simplecrypt.cpp
@@ -82,7 +82,7 @@ namespace BlackMisc
             return encryptToByteArray(plaintextArray);
         }
 
-        QByteArray SimpleCrypt::encryptToByteArray(QByteArray plaintext)
+        QByteArray SimpleCrypt::encryptToByteArray(const QByteArray &plaintext)
         {
             if (m_keyParts.isEmpty())
             {
@@ -159,7 +159,7 @@ namespace BlackMisc
             return cypherString;
         }
 
-        QString SimpleCrypt::encryptToString(QByteArray plaintext)
+        QString SimpleCrypt::encryptToString(const QByteArray &plaintext)
         {
             QByteArray cypher = encryptToByteArray(plaintext);
             QString cypherString = QString::fromLatin1(cypher.toBase64());
@@ -175,7 +175,7 @@ namespace BlackMisc
             return plaintext;
         }
 
-        QString SimpleCrypt::decryptToString(QByteArray cypher)
+        QString SimpleCrypt::decryptToString(const QByteArray &cypher)
         {
             QByteArray ba = decryptToByteArray(cypher);
             QString plaintext = QString::fromUtf8(ba, ba.size());
@@ -191,7 +191,7 @@ namespace BlackMisc
             return ba;
         }
 
-        QByteArray SimpleCrypt::decryptToByteArray(QByteArray cypher)
+        QByteArray SimpleCrypt::decryptToByteArray(const QByteArray &cypher)
         {
             if (m_keyParts.isEmpty())
             {
diff --git a/src/blackmisc/thirdparty/simplecrypt.h b/src/blackmisc/thirdparty/simplecrypt.h
index e601eafd0..f917f44b5 100644
--- a/src/blackmisc/thirdparty/simplecrypt.h
+++ b/src/blackmisc/thirdparty/simplecrypt.h
@@ -147,7 +147,7 @@ namespace BlackMisc
               a cyphertext the result. The result is a base64 encoded version of the binary array that is the
               actual result of the encryption, so it can be stored easily in a text format.
               */
-            QString encryptToString(QByteArray plaintext) ;
+            QString encryptToString(const QByteArray &plaintext) ;
 
             /**
               Encrypts the @arg plaintext string with the key the class was initialized with, and returns
@@ -165,7 +165,7 @@ namespace BlackMisc
               This method returns a byte array, that is useable for storing a binary format. If you need
               a string you can store in a text file, use encryptToString() instead.
               */
-            QByteArray encryptToByteArray(QByteArray plaintext) ;
+            QByteArray encryptToByteArray(const QByteArray &plaintext) ;
 
             /**
               Decrypts a cyphertext string encrypted with this class with the set key back to the
@@ -192,7 +192,7 @@ namespace BlackMisc
               If an error occured, such as non-matching keys between encryption and decryption,
               an empty string or a string containing nonsense may be returned.
               */
-            QString decryptToString(QByteArray cypher) ;
+            QString decryptToString(const QByteArray &cypher) ;
 
             /**
               Decrypts a cyphertext binary encrypted with this class with the set key back to the
@@ -201,7 +201,7 @@ namespace BlackMisc
               If an error occured, such as non-matching keys between encryption and decryption,
               an empty string or a string containing nonsense may be returned.
               */
-            QByteArray decryptToByteArray(QByteArray cypher) ;
+            QByteArray decryptToByteArray(const QByteArray &cypher) ;
 
             /**
               Enum to describe options that have been used for the encryption. Currently only one, but
diff --git a/src/blackmisc/valuecache.cpp b/src/blackmisc/valuecache.cpp
index 1c9c34737..2444b6f21 100644
--- a/src/blackmisc/valuecache.cpp
+++ b/src/blackmisc/valuecache.cpp
@@ -608,7 +608,7 @@ namespace BlackMisc
 
     struct CValuePage::Element
     {
-        Element(const QString &key, const QString &name, int metaType, Validator validator, const CVariant &defaultValue) :
+        Element(const QString &key, const QString &name, int metaType, const Validator &validator, const CVariant &defaultValue) :
             m_key(key), m_name(name), m_metaType(metaType), m_validator(validator), m_default(defaultValue)
         {}
         const QString m_key;
@@ -624,7 +624,7 @@ namespace BlackMisc
         bool m_saved = false;
     };
 
-    CValuePage::Element &CValuePage::createElement(const QString &keyTemplate, const QString &name, int metaType, Validator validator, const CVariant &defaultValue)
+    CValuePage::Element &CValuePage::createElement(const QString &keyTemplate, const QString &name, int metaType, const Validator &validator, const CVariant &defaultValue)
     {
         if (parent()->objectName().isEmpty() && keyTemplate.contains("%OwnerName%"))
         {
@@ -667,7 +667,7 @@ namespace BlackMisc
         return element;
     }
 
-    void CValuePage::setNotifySlot(Element &element, NotifySlot slot)
+    void CValuePage::setNotifySlot(Element &element, const NotifySlot &slot)
     {
         element.m_notifySlot = slot;
     }
diff --git a/src/blackmisc/valuecache.h b/src/blackmisc/valuecache.h
index 974be09d2..3e246f40d 100644
--- a/src/blackmisc/valuecache.h
+++ b/src/blackmisc/valuecache.h
@@ -456,7 +456,7 @@ namespace BlackMisc
 
     protected:
         //! \private Connect a function to be called (only once) when the owner's objectName changes.
-        void onOwnerNameChanged(std::function<void()> function)
+        void onOwnerNameChanged(const std::function<void()> &function)
         {
             connectOnce(m_page->parent(), &QObject::objectNameChanged, [function](const QString &) { function(); });
         }
diff --git a/src/blackmisc/valuecacheprivate.h b/src/blackmisc/valuecacheprivate.h
index 373ca9a9c..77622b101 100644
--- a/src/blackmisc/valuecacheprivate.h
+++ b/src/blackmisc/valuecacheprivate.h
@@ -84,10 +84,10 @@ namespace BlackMisc
             //! \param metaType The Qt metatype ID of the value object's expected type.
             //! \param validator Optional functor which returns true if the value is valid.
             //! \param defaultValue Optional value which is used in case the value is invalid.
-            Element &createElement(const QString &key, const QString &name, int metaType, Validator validator, const CVariant &defaultValue);
+            Element &createElement(const QString &key, const QString &name, int metaType, const Validator &validator, const CVariant &defaultValue);
 
             //! Set the functor to call to notify that the value corresponding to the element's key was modified.
-            void setNotifySlot(Element &element, NotifySlot slot);
+            void setNotifySlot(Element &element, const NotifySlot &slot);
 
             //! True if the currently paged value corresponds to a valid key.
             bool isInitialized(const Element &element) const;
diff --git a/src/blackmisc/worker.cpp b/src/blackmisc/worker.cpp
index 04bca58c9..98afb2c53 100644
--- a/src/blackmisc/worker.cpp
+++ b/src/blackmisc/worker.cpp
@@ -59,7 +59,7 @@ namespace BlackMisc
         Q_UNUSED(ok);
     }
 
-    CWorker *CWorker::fromTaskImpl(QObject *owner, const QString &name, int typeId, std::function<CVariant()> task)
+    CWorker *CWorker::fromTaskImpl(QObject *owner, const QString &name, int typeId, const std::function<CVariant()> &task)
     {
         auto *worker = new CWorker(task);
         emit worker->aboutToStart();
diff --git a/src/blackmisc/worker.h b/src/blackmisc/worker.h
index 7dca5f972..b500ab2dd 100644
--- a/src/blackmisc/worker.h
+++ b/src/blackmisc/worker.h
@@ -268,8 +268,8 @@ namespace BlackMisc
         void ps_runTask();
 
     private:
-        CWorker(std::function<CVariant()> task) : m_task(task) {}
-        static CWorker *fromTaskImpl(QObject *owner, const QString &name, int typeId, std::function<CVariant()> task);
+        CWorker(const std::function<CVariant()> &task) : m_task(task) {}
+        static CWorker *fromTaskImpl(QObject *owner, const QString &name, int typeId, const std::function<CVariant()> &task);
 
         template <typename R>
         R resultNoWait() { Q_ASSERT(m_result.canConvert<R>()); return m_result.value<R>(); }
diff --git a/src/plugins/simulator/emulated/simulatoremulated.cpp b/src/plugins/simulator/emulated/simulatoremulated.cpp
index ecbe6907b..7e883e68e 100644
--- a/src/plugins/simulator/emulated/simulatoremulated.cpp
+++ b/src/plugins/simulator/emulated/simulatoremulated.cpp
@@ -387,7 +387,7 @@ namespace BlackSimPlugin
             },
             Qt::QueuedConnection));
 
-            m_connectionGuard.append(connect(this, &ISimulator::ownAircraftModelChanged, this, [ = ](CAircraftModel model)
+            m_connectionGuard.append(connect(this, &ISimulator::ownAircraftModelChanged, this, [ = ](const CAircraftModel &model)
             {
                 if (!m_monitorWidget) return;
                 m_monitorWidget->appendSendingCall("ownAircraftModelChanged", model.toQString());
diff --git a/src/plugins/simulator/fsxcommon/simconnectsymbols.cpp b/src/plugins/simulator/fsxcommon/simconnectsymbols.cpp
index ac88fcb31..419ff3f67 100644
--- a/src/plugins/simulator/fsxcommon/simconnectsymbols.cpp
+++ b/src/plugins/simulator/fsxcommon/simconnectsymbols.cpp
@@ -16,6 +16,8 @@
 #include <SimConnect.h>
 #include <array>
 
+// clazy:excludeall=function-args-by-ref
+
 using namespace BlackMisc;
 
 bool loadAndResolveSimConnect(bool manifestProbing)
diff --git a/tests/blackcore/vatsim/testnetwork/expect.h b/tests/blackcore/vatsim/testnetwork/expect.h
index a9f52c10d..11e881a2c 100644
--- a/tests/blackcore/vatsim/testnetwork/expect.h
+++ b/tests/blackcore/vatsim/testnetwork/expect.h
@@ -171,7 +171,7 @@ namespace BlackCoreTest
         mutable ConnectGuard m_guard;
 
         mutable std::function<void(const ExpectUnit *)> m_onDone;
-        void onDone(std::function<void(const ExpectUnit *)> callback) const { m_onDone = callback; }
+        void onDone(const std::function<void(const ExpectUnit *)> &callback) const { m_onDone = callback; }
 
         // Helper traits class. Given T is a pointer-to-member-of-U, ClassOf<T>::type is U.
         template <class T> struct ClassOf;