diff --git a/src/api/api_database.h b/src/api/api_database.h
index 50f83aa7..cabe0a83 100644
--- a/src/api/api_database.h
+++ b/src/api/api_database.h
@@ -38,7 +38,7 @@
 #include "loot/vertex.h"
 
 namespace loot {
-struct ApiDatabase : public DatabaseInterface {
+struct ApiDatabase final : public DatabaseInterface {
   explicit ApiDatabase(std::shared_ptr<ConditionEvaluator> conditionEvaluator);
 
   void LoadLists(const std::filesystem::path& masterlist_path,
diff --git a/src/api/error_categories.cpp b/src/api/error_categories.cpp
index 252a72f4..c29544e8 100644
--- a/src/api/error_categories.cpp
+++ b/src/api/error_categories.cpp
@@ -29,11 +29,11 @@
 namespace loot {
 namespace detail {
 class libloadorder_category : public std::error_category {
-  virtual const char* name() const noexcept { return "libloadorder"; }
+  const char* name() const noexcept override { return "libloadorder"; }
 
-  virtual std::string message(int) const { return "Libloadorder error"; }
+  std::string message(int) const override { return "Libloadorder error"; }
 
-  virtual bool equivalent(const std::error_code& code) const noexcept {
+  bool equivalent(const std::error_code& code, int) const noexcept override {
     return code.category().name() == name();
   }
 };
diff --git a/src/api/game/game.cpp b/src/api/game/game.cpp
index 8b566bf8..982b3c0f 100644
--- a/src/api/game/game.cpp
+++ b/src/api/game/game.cpp
@@ -101,7 +101,6 @@ bool Game::IsValidPlugin(const std::string& plugin) const {
 void Game::LoadPlugins(const std::vector<std::string>& plugins,
                        bool loadHeadersOnly) {
   auto logger = getLogger();
-  uintmax_t meanFileSize = 0;
   std::multimap<uintmax_t, string> sizeMap;
 
   // First get the plugin sizes.
@@ -110,7 +109,6 @@ void Game::LoadPlugins(const std::vector<std::string>& plugins,
       throw std::invalid_argument("\"" + plugin + "\" is not a valid plugin");
 
     uintmax_t fileSize = Plugin::GetFileSize(DataPath() / u8path(plugin));
-    meanFileSize += fileSize;
 
     // Trim .ghost extension if present.
     if (boost::iends_with(plugin, ".ghost"))
@@ -118,7 +116,6 @@ void Game::LoadPlugins(const std::vector<std::string>& plugins,
     else
       sizeMap.emplace(fileSize, plugin);
   }
-  meanFileSize /= sizeMap.size();  // Rounding error, but not important.
 
   // Get the number of threads to use.
   // hardware_concurrency() may be zero, if so then use only one thread.
diff --git a/src/api/game/game.h b/src/api/game/game.h
index 5726aa97..2164576e 100644
--- a/src/api/game/game.h
+++ b/src/api/game/game.h
@@ -34,7 +34,7 @@
 #include "loot/game_interface.h"
 
 namespace loot {
-class Game : public GameInterface {
+class Game final : public GameInterface {
 public:
   explicit Game(const GameType gameType,
                 const std::filesystem::path& gamePath,
diff --git a/src/api/plugin.h b/src/api/plugin.h
index 7d58cf79..9c3d8fc0 100644
--- a/src/api/plugin.h
+++ b/src/api/plugin.h
@@ -40,7 +40,7 @@
 namespace loot {
 class GameCache;
 
-class Plugin : public PluginInterface {
+class Plugin final : public PluginInterface {
 public:
   explicit Plugin(const GameType gameType,
                   std::shared_ptr<GameCache> gameCache,
diff --git a/src/api/sorting/plugin_graph.cpp b/src/api/sorting/plugin_graph.cpp
index 88ca6535..139a17ad 100644
--- a/src/api/sorting/plugin_graph.cpp
+++ b/src/api/sorting/plugin_graph.cpp
@@ -283,6 +283,7 @@ std::optional<vertex_t> PluginGraph::GetVertexByName(
 
 void PluginGraph::CheckForCycles() const {
   auto logger = getLogger();
+  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDelete)
   if (logger) {
     logger->trace("Checking plugin graph for cycles...");
   }
@@ -290,6 +291,7 @@ void PluginGraph::CheckForCycles() const {
   std::map<vertex_t, size_t> indexMap;
   auto vertexIndexMap = vertex_map_t(indexMap);
   size_t i = 0;
+  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDelete)
   BGL_FORALL_VERTICES(v, graph_, RawPluginGraph) {
     put(vertexIndexMap, v, i++);
   }
diff --git a/src/tests/api/internals/plugin_test.h b/src/tests/api/internals/plugin_test.h
index 75b3731d..c4e3b8dc 100644
--- a/src/tests/api/internals/plugin_test.h
+++ b/src/tests/api/internals/plugin_test.h
@@ -38,9 +38,9 @@ protected:
       lowercaseBlankEsp("blank.esp"),
       nonAsciiEsp(u8"non\u00C1scii.esp"),
       otherNonAsciiEsp(u8"other non\u00C1scii.esp"),
-      blankArchive("Blank" + GetArchiveFileExtension(game_.Type())),
+      blankArchive("Blank" + GetArchiveFileExtension(GetParam())),
       blankSuffixArchive("Blank - Different - suffix" +
-                         GetArchiveFileExtension(game_.Type())),
+                         GetArchiveFileExtension(GetParam())),
       game_(GetParam(), dataPath.parent_path(), localPath) {}
 
   void SetUp() {
@@ -136,7 +136,7 @@ private:
   }
 };
 
-class OtherPluginType : public PluginInterface {
+class OtherPluginType final : public PluginInterface {
 public:
   std::string GetName() const { return ""; }
   std::optional<float> GetHeaderVersion() const { return 0.0f; }