diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8801da4a..65688c96 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -498,6 +498,7 @@ if(RUN_CLANG_TIDY)
         "cppcoreguidelines-pro-bounds-pointer-arithmetic"
         "cppcoreguidelines-pro-type-const-cast"
         "cppcoreguidelines-pro-type-cstyle-cast"
+        "cppcoreguidelines-pro-type-member-init"
         "cppcoreguidelines-pro-type-reinterpret-cast"
         "cppcoreguidelines-pro-type-static-cast-downcast"
         "cppcoreguidelines-pro-type-union-access"
diff --git a/include/loot/struct/simple_message.h b/include/loot/struct/simple_message.h
index dde52ab9..aac3e5ba 100644
--- a/include/loot/struct/simple_message.h
+++ b/include/loot/struct/simple_message.h
@@ -34,7 +34,7 @@ namespace loot {
  */
 struct SimpleMessage {
   /** The type of the message. */
-  MessageType type;
+  MessageType type{MessageType::say};
 
   /** The language the message string is written in. */
   std::string language;
diff --git a/src/api/api_database.h b/src/api/api_database.h
index d3548d6f..a69b8ac7 100644
--- a/src/api/api_database.h
+++ b/src/api/api_database.h
@@ -59,7 +59,7 @@ struct ApiDatabase final : public DatabaseInterface {
 
   std::vector<Group> GetGroups(bool includeUserMetadata = true) const override;
   std::vector<Group> GetUserGroups() const override;
-  void SetUserGroups(const std::vector<Group>& groups);
+  void SetUserGroups(const std::vector<Group>& groups) override;
   std::vector<Vertex> GetGroupsPath(
       const std::string& fromGroupName,
       const std::string& toGroupName) const override;
diff --git a/src/api/helpers/crc.cpp b/src/api/helpers/crc.cpp
index abee0014..653ec9d4 100644
--- a/src/api/helpers/crc.cpp
+++ b/src/api/helpers/crc.cpp
@@ -56,7 +56,7 @@ uint32_t GetCrc32(const std::filesystem::path& filename) {
     ifile.exceptions(std::ios_base::badbit | std::ios_base::failbit);
 
     static constexpr size_t BUFFER_SIZE = 8192;
-    std::array<char, BUFFER_SIZE> buffer;
+    std::array<char, BUFFER_SIZE> buffer{};
     boost::crc_32_type result;
     size_t bytesLeft = GetStreamSize(ifile);
     while (bytesLeft > 0) {
diff --git a/src/tests/api/interface/api_game_operations_test.h b/src/tests/api/interface/api_game_operations_test.h
index cb57e7a8..8c283025 100644
--- a/src/tests/api/interface/api_game_operations_test.h
+++ b/src/tests/api/interface/api_game_operations_test.h
@@ -46,7 +46,7 @@ protected:
       errorMessage("Obsolete. Remove this and install Enhanced Weather."),
       generalMasterlistMessage("A general masterlist message.") {}
 
-  virtual void SetUp() override {
+  void SetUp() override {
     CommonGameTestFixture::SetUp();
 
     ASSERT_FALSE(std::filesystem::exists(masterlistPath));
diff --git a/src/tests/api/internals/metadata_list_test.h b/src/tests/api/internals/metadata_list_test.h
index 4484de3d..5f67951b 100644
--- a/src/tests/api/internals/metadata_list_test.h
+++ b/src/tests/api/internals/metadata_list_test.h
@@ -40,7 +40,7 @@ protected:
           {metadataFilesPath / "invalid" / "non_map_root.yaml",
            metadataFilesPath / "invalid" / "non_unique.yaml"}) {}
 
-  inline virtual void SetUp() override {
+  inline void SetUp() override {
     CommonGameTestFixture::SetUp();
 
     using std::filesystem::copy;
diff --git a/src/tests/common_game_test_fixture.h b/src/tests/common_game_test_fixture.h
index 5f91ecf7..b474df4a 100644
--- a/src/tests/common_game_test_fixture.h
+++ b/src/tests/common_game_test_fixture.h
@@ -146,7 +146,7 @@ protected:
     ASSERT_TRUE(std::filesystem::exists(dataPath / filename));
   }
 
-  void TearDown() {
+  void TearDown() override {
     // Grant write permissions to everything in rootTestPath
     // in case the test made anything read only.
     for (const auto& path :