diff --git a/src/openrct2-ui/UiContext.Win32.cpp b/src/openrct2-ui/UiContext.Win32.cpp
index 8a377b5eec..2d7afc879a 100644
--- a/src/openrct2-ui/UiContext.Win32.cpp
+++ b/src/openrct2-ui/UiContext.Win32.cpp
@@ -232,7 +232,7 @@ namespace OpenRCT2::Ui
             return result;
         }
 
-        static std::wstring GetFilterString(const std::vector<FileDialogDesc::Filter> filters)
+        static std::wstring GetFilterString(const std::vector<FileDialogDesc::Filter>& filters)
         {
             std::wstringstream filtersb;
             for (const auto& filter : filters)
diff --git a/src/openrct2-ui/UiContext.cpp b/src/openrct2-ui/UiContext.cpp
index 7e7c1aa22c..9031f447a1 100644
--- a/src/openrct2-ui/UiContext.cpp
+++ b/src/openrct2-ui/UiContext.cpp
@@ -123,7 +123,7 @@ public:
 
     ~UiContext() override
     {
-        CloseWindow();
+        UiContext::CloseWindow();
         delete _windowManager;
         SDL_QuitSubSystem(SDL_INIT_VIDEO);
         delete _platformUiContext;
@@ -179,11 +179,8 @@ public:
         if (mode == FULLSCREEN_MODE::FULLSCREEN)
         {
             SDL_SetWindowFullscreen(_window, 0);
-        }
 
-        // Set window size
-        if (mode == FULLSCREEN_MODE::FULLSCREEN)
-        {
+            // Set window size
             UpdateFullscreenResolutions();
             Resolution resolution = GetClosestResolution(gConfigGeneral.fullscreen_width, gConfigGeneral.fullscreen_height);
             SDL_SetWindowSize(_window, resolution.Width, resolution.Height);
@@ -598,7 +595,7 @@ public:
         {
             scaleQuality = ScaleQuality::Linear;
         }
-        snprintf(scaleQualityBuffer, sizeof(scaleQualityBuffer), "%u", static_cast<int32_t>(scaleQuality));
+        snprintf(scaleQualityBuffer, sizeof(scaleQualityBuffer), "%d", static_cast<int32_t>(scaleQuality));
         SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, scaleQualityBuffer);
 
         int32_t width, height;
diff --git a/src/openrct2-ui/audio/AudioChannel.cpp b/src/openrct2-ui/audio/AudioChannel.cpp
index 8a356f1904..ad4875f4c2 100644
--- a/src/openrct2-ui/audio/AudioChannel.cpp
+++ b/src/openrct2-ui/audio/AudioChannel.cpp
@@ -47,9 +47,9 @@ namespace OpenRCT2::Audio
     public:
         AudioChannelImpl()
         {
-            SetRate(1);
-            SetVolume(MIXER_VOLUME_MAX);
-            SetPan(0.5f);
+            AudioChannelImpl::SetRate(1);
+            AudioChannelImpl::SetVolume(MIXER_VOLUME_MAX);
+            AudioChannelImpl::SetPan(0.5f);
         }
 
         ~AudioChannelImpl() override
diff --git a/src/openrct2-ui/audio/AudioMixer.cpp b/src/openrct2-ui/audio/AudioMixer.cpp
index 0da4428bbf..3af92b91f7 100644
--- a/src/openrct2-ui/audio/AudioMixer.cpp
+++ b/src/openrct2-ui/audio/AudioMixer.cpp
@@ -56,7 +56,7 @@ namespace OpenRCT2::Audio
 
         ~AudioMixerImpl() override
         {
-            Close();
+            AudioMixerImpl::Close();
             delete _nullSource;
         }
 
diff --git a/src/openrct2-ui/drawing/engines/HardwareDisplayDrawingEngine.cpp b/src/openrct2-ui/drawing/engines/HardwareDisplayDrawingEngine.cpp
index 8f0325938a..5fb9e20136 100644
--- a/src/openrct2-ui/drawing/engines/HardwareDisplayDrawingEngine.cpp
+++ b/src/openrct2-ui/drawing/engines/HardwareDisplayDrawingEngine.cpp
@@ -134,7 +134,7 @@ public:
             }
 
             char scaleQualityBuffer[4];
-            snprintf(scaleQualityBuffer, sizeof(scaleQualityBuffer), "%u", static_cast<int32_t>(scaleQuality));
+            snprintf(scaleQualityBuffer, sizeof(scaleQualityBuffer), "%d", static_cast<int32_t>(scaleQuality));
             SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "0");
             _screenTexture = SDL_CreateTexture(_sdlRenderer, pixelFormat, SDL_TEXTUREACCESS_STREAMING, width, height);
             SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, scaleQualityBuffer);
diff --git a/src/openrct2-ui/drawing/engines/opengl/OpenGLShaderProgram.cpp b/src/openrct2-ui/drawing/engines/opengl/OpenGLShaderProgram.cpp
index 2056a13a18..a56ce93c62 100644
--- a/src/openrct2-ui/drawing/engines/opengl/OpenGLShaderProgram.cpp
+++ b/src/openrct2-ui/drawing/engines/opengl/OpenGLShaderProgram.cpp
@@ -21,9 +21,8 @@
 using namespace OpenRCT2;
 
 OpenGLShader::OpenGLShader(const char* name, GLenum type)
+    : _type(type)
 {
-    _type = type;
-
     auto path = GetPath(name);
     auto sourceCode = ReadSourceCode(path);
     auto sourceCodeStr = sourceCode.c_str();
diff --git a/src/openrct2-ui/drawing/engines/opengl/TextureCache.h b/src/openrct2-ui/drawing/engines/opengl/TextureCache.h
index 9c0125b0b7..f624da0df7 100644
--- a/src/openrct2-ui/drawing/engines/opengl/TextureCache.h
+++ b/src/openrct2-ui/drawing/engines/opengl/TextureCache.h
@@ -91,9 +91,9 @@ private:
 
 public:
     Atlas(GLuint index, int32_t imageSize)
+        : _index(index)
+        , _imageSize(imageSize)
     {
-        _index = index;
-        _imageSize = imageSize;
     }
 
     void Initialise(int32_t atlasWidth, int32_t atlasHeight)
diff --git a/src/openrct2-ui/windows/LoadSave.cpp b/src/openrct2-ui/windows/LoadSave.cpp
index ba4c410571..74585956a9 100644
--- a/src/openrct2-ui/windows/LoadSave.cpp
+++ b/src/openrct2-ui/windows/LoadSave.cpp
@@ -117,13 +117,13 @@ enum
 
 struct LoadSaveListItem
 {
-    std::string name;
-    std::string path;
-    time_t date_modified;
-    std::string date_formatted;
-    std::string time_formatted;
-    uint8_t type;
-    bool loaded;
+    std::string name{};
+    std::string path{};
+    time_t date_modified{ 0 };
+    std::string date_formatted{};
+    std::string time_formatted{};
+    uint8_t type{ 0 };
+    bool loaded{ false };
 };
 
 static std::function<void(int32_t result, std::string_view)> _loadSaveCallback;
diff --git a/src/openrct2-ui/windows/ObjectLoadError.cpp b/src/openrct2-ui/windows/ObjectLoadError.cpp
index a608cf8aeb..ed1b1e70a0 100644
--- a/src/openrct2-ui/windows/ObjectLoadError.cpp
+++ b/src/openrct2-ui/windows/ObjectLoadError.cpp
@@ -150,7 +150,7 @@ private:
         _nextDownloadQueued = true;
     }
 
-    void DownloadObject(const rct_object_entry& entry, const std::string name, const std::string url)
+    void DownloadObject(const rct_object_entry& entry, const std::string& name, const std::string& url)
     {
         try
         {
diff --git a/src/openrct2/network/Socket.cpp b/src/openrct2/network/Socket.cpp
index 2bf4d8dd30..73bca48b76 100644
--- a/src/openrct2/network/Socket.cpp
+++ b/src/openrct2/network/Socket.cpp
@@ -631,11 +631,11 @@ public:
 
 private:
     explicit TcpSocket(SOCKET socket, const std::string& hostName, const std::string& ipAddress)
+        : _status(SocketStatus::Connected)
+        , _socket(socket)
+        , _ipAddress(ipAddress)
+        , _hostName(hostName)
     {
-        _socket = socket;
-        _hostName = hostName;
-        _ipAddress = ipAddress;
-        _status = SocketStatus::Connected;
     }
 
     void CloseSocket()
@@ -833,10 +833,10 @@ public:
 
 private:
     explicit UdpSocket(SOCKET socket, const std::string& hostName)
+        : _status(SocketStatus::Connected)
+        , _socket(socket)
+        , _hostName(hostName)
     {
-        _socket = socket;
-        _hostName = hostName;
-        _status = SocketStatus::Connected;
     }
 
     SOCKET CreateSocket()
diff --git a/test/tests/AssertHelpers.hpp b/test/tests/AssertHelpers.hpp
index 07f5213946..46398badcf 100644
--- a/test/tests/AssertHelpers.hpp
+++ b/test/tests/AssertHelpers.hpp
@@ -13,7 +13,7 @@
 #include <initializer_list>
 #include <vector>
 
-template<typename T, typename TExpected> static void AssertVector(std::vector<T> actual, TExpected expected)
+template<typename T, typename TExpected> static void AssertVector(const std::vector<T>& actual, TExpected expected)
 {
     ASSERT_EQ(actual.size(), expected.size()) << "Expected vector of size " << expected.size() << ", but was " << actual.size();
     size_t i = 0;
@@ -24,7 +24,7 @@ template<typename T, typename TExpected> static void AssertVector(std::vector<T>
     }
 }
 
-template<typename T> static void AssertVector(std::vector<T> actual, std::initializer_list<T> expected)
+template<typename T> static void AssertVector(const std::vector<T>& actual, std::initializer_list<T> expected)
 {
     AssertVector<T, std::initializer_list<T>>(actual, expected);
 }