diff --git a/src/catch2/internal/catch_console_colour.cpp b/src/catch2/internal/catch_console_colour.cpp
index 099a6c59..e1238816 100644
--- a/src/catch2/internal/catch_console_colour.cpp
+++ b/src/catch2/internal/catch_console_colour.cpp
@@ -85,7 +85,7 @@ namespace Catch {
     namespace {
         //! A do-nothing implementation of colour, used as fallback for unknown
         //! platforms, and when the user asks to deactivate all colours.
-        class NoColourImpl : public ColourImpl {
+        class NoColourImpl final : public ColourImpl {
         public:
             NoColourImpl( IStream* stream ): ColourImpl( stream ) {}
 
@@ -103,7 +103,7 @@ namespace Catch {
 namespace Catch {
 namespace {
 
-    class Win32ColourImpl : public ColourImpl {
+    class Win32ColourImpl final : public ColourImpl {
     public:
         Win32ColourImpl(IStream* stream):
             ColourImpl(stream) {
@@ -169,7 +169,7 @@ namespace {
 namespace Catch {
 namespace {
 
-    class ANSIColourImpl : public ColourImpl {
+    class ANSIColourImpl final : public ColourImpl {
     public:
         ANSIColourImpl( IStream* stream ): ColourImpl( stream ) {}
 
diff --git a/src/catch2/internal/catch_istream.cpp b/src/catch2/internal/catch_istream.cpp
index 489396ec..bf0f66e4 100644
--- a/src/catch2/internal/catch_istream.cpp
+++ b/src/catch2/internal/catch_istream.cpp
@@ -24,7 +24,7 @@ namespace Catch {
 namespace Detail {
     namespace {
         template<typename WriterF, std::size_t bufferSize=256>
-        class StreamBufImpl : public std::streambuf {
+        class StreamBufImpl final : public std::streambuf {
             char data[bufferSize];
             WriterF m_writer;
 
@@ -72,7 +72,7 @@ namespace Detail {
 
         ///////////////////////////////////////////////////////////////////////////
 
-        class FileStream : public IStream {
+        class FileStream final : public IStream {
             std::ofstream m_ofs;
         public:
             FileStream( std::string const& filename ) {
@@ -89,7 +89,7 @@ namespace Detail {
 
         ///////////////////////////////////////////////////////////////////////////
 
-        class CoutStream : public IStream {
+        class CoutStream final : public IStream {
             std::ostream m_os;
         public:
             // Store the streambuf from cout up-front because
@@ -118,7 +118,7 @@ namespace Detail {
 
         ///////////////////////////////////////////////////////////////////////////
 
-        class DebugOutStream : public IStream {
+        class DebugOutStream final : public IStream {
             Detail::unique_ptr<StreamBufImpl<OutputDebugWriter>> m_streamBuf;
             std::ostream m_os;
         public:
diff --git a/src/catch2/internal/catch_run_context.cpp b/src/catch2/internal/catch_run_context.cpp
index 8ffa7d47..11fcda45 100644
--- a/src/catch2/internal/catch_run_context.cpp
+++ b/src/catch2/internal/catch_run_context.cpp
@@ -27,7 +27,7 @@ namespace Catch {
 
     namespace Generators {
         namespace {
-            struct GeneratorTracker : TestCaseTracking::TrackerBase,
+            struct GeneratorTracker final : TestCaseTracking::TrackerBase,
                                       IGeneratorTracker {
                 GeneratorBasePtr m_generator;
 
@@ -36,7 +36,7 @@ namespace Catch {
                     TrackerContext& ctx,
                     ITracker* parent ):
                     TrackerBase( CATCH_MOVE( nameAndLocation ), ctx, parent ) {}
-                ~GeneratorTracker() override;
+                ~GeneratorTracker() override = default;
 
                 static GeneratorTracker*
                 acquire( TrackerContext& ctx,
@@ -161,7 +161,6 @@ namespace Catch {
                     m_generator = CATCH_MOVE( generator );
                 }
             };
-            GeneratorTracker::~GeneratorTracker() = default;
         } // namespace
     }
 
diff --git a/src/catch2/internal/catch_run_context.hpp b/src/catch2/internal/catch_run_context.hpp
index ea2ca7c8..de6999e5 100644
--- a/src/catch2/internal/catch_run_context.hpp
+++ b/src/catch2/internal/catch_run_context.hpp
@@ -29,7 +29,7 @@ namespace Catch {
 
     ///////////////////////////////////////////////////////////////////////////
 
-    class RunContext : public IResultCapture {
+    class RunContext final : public IResultCapture {
 
     public:
         RunContext( RunContext const& ) = delete;