diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 9bef6cbb..d115b3dd 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -106,6 +106,7 @@ set(IMPL_HEADERS
   ${SOURCES_DIR}/internal/catch_preprocessor_remove_parens.hpp
   ${SOURCES_DIR}/internal/catch_random_number_generator.hpp
   ${SOURCES_DIR}/internal/catch_random_seed_generation.hpp
+  ${SOURCES_DIR}/internal/catch_registry_hub.hpp
   ${SOURCES_DIR}/internal/catch_reporter_registry.hpp
   ${SOURCES_DIR}/internal/catch_reporter_spec_parser.hpp
   ${SOURCES_DIR}/internal/catch_result_type.hpp
@@ -145,7 +146,6 @@ set(IMPL_SOURCES
   ${SOURCES_DIR}/catch_config.cpp
   ${SOURCES_DIR}/catch_get_random_seed.cpp
   ${SOURCES_DIR}/catch_message.cpp
-  ${SOURCES_DIR}/catch_registry_hub.cpp
   ${SOURCES_DIR}/catch_session.cpp
   ${SOURCES_DIR}/catch_tag_alias_autoregistrar.cpp
   ${SOURCES_DIR}/catch_test_case_info.cpp
@@ -181,6 +181,7 @@ set(IMPL_SOURCES
   ${SOURCES_DIR}/internal/catch_polyfills.cpp
   ${SOURCES_DIR}/internal/catch_random_number_generator.cpp
   ${SOURCES_DIR}/internal/catch_random_seed_generation.cpp
+  ${SOURCES_DIR}/internal/catch_registry_hub.cpp
   ${SOURCES_DIR}/internal/catch_reporter_registry.cpp
   ${SOURCES_DIR}/internal/catch_reporter_spec_parser.cpp
   ${SOURCES_DIR}/internal/catch_result_type.cpp
@@ -213,7 +214,6 @@ set(INTERFACE_HEADERS
   ${SOURCES_DIR}/interfaces/catch_interfaces_config.hpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_exception.hpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_generatortracker.hpp
-  ${SOURCES_DIR}/interfaces/catch_interfaces_registry_hub.hpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_reporter.hpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_reporter_factory.hpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_testcase.hpp
@@ -223,7 +223,6 @@ set(INTERFACE_SOURCES
   ${SOURCES_DIR}/interfaces/catch_interfaces_config.cpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_exception.cpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_generatortracker.cpp
-  ${SOURCES_DIR}/interfaces/catch_interfaces_registry_hub.cpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_reporter.cpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_reporter_factory.cpp
   ${SOURCES_DIR}/interfaces/catch_interfaces_testcase.cpp
diff --git a/src/catch2/benchmark/catch_benchmark.hpp b/src/catch2/benchmark/catch_benchmark.hpp
index 1cf10be6..6683dc05 100644
--- a/src/catch2/benchmark/catch_benchmark.hpp
+++ b/src/catch2/benchmark/catch_benchmark.hpp
@@ -14,6 +14,7 @@
 #include <catch2/internal/catch_compiler_capabilities.hpp>
 #include <catch2/internal/catch_context.hpp>
 #include <catch2/interfaces/catch_interfaces_reporter.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/internal/catch_unique_name.hpp>
 #include <catch2/internal/catch_move_and_forward.hpp>
 #include <catch2/benchmark/catch_chronometer.hpp>
@@ -26,6 +27,7 @@
 #include <catch2/benchmark/detail/catch_benchmark_function.hpp>
 #include <catch2/benchmark/detail/catch_run_for_at_least.hpp>
 
+
 #include <algorithm>
 #include <functional>
 #include <string>
diff --git a/src/catch2/benchmark/detail/catch_complete_invoke.hpp b/src/catch2/benchmark/detail/catch_complete_invoke.hpp
index 49db413e..d24da37d 100644
--- a/src/catch2/benchmark/detail/catch_complete_invoke.hpp
+++ b/src/catch2/benchmark/detail/catch_complete_invoke.hpp
@@ -13,7 +13,6 @@
 #include <catch2/internal/catch_test_failure_exception.hpp>
 #include <catch2/internal/catch_meta.hpp>
 #include <catch2/interfaces/catch_interfaces_capture.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
 #include <catch2/internal/catch_move_and_forward.hpp>
 
 #include <type_traits>
diff --git a/src/catch2/catch_all.hpp b/src/catch2/catch_all.hpp
index be146421..d0fd8c6d 100644
--- a/src/catch2/catch_all.hpp
+++ b/src/catch2/catch_all.hpp
@@ -89,6 +89,7 @@
 #include <catch2/internal/catch_preprocessor_remove_parens.hpp>
 #include <catch2/internal/catch_random_number_generator.hpp>
 #include <catch2/internal/catch_random_seed_generation.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/internal/catch_reporter_registry.hpp>
 #include <catch2/internal/catch_reporter_spec_parser.hpp>
 #include <catch2/internal/catch_result_type.hpp>
diff --git a/src/catch2/catch_registry_hub.cpp b/src/catch2/catch_registry_hub.cpp
deleted file mode 100644
index f47d1742..00000000
--- a/src/catch2/catch_registry_hub.cpp
+++ /dev/null
@@ -1,105 +0,0 @@
-
-//              Copyright Catch2 Authors
-// Distributed under the Boost Software License, Version 1.0.
-//   (See accompanying file LICENSE.txt or copy at
-//        https://www.boost.org/LICENSE_1_0.txt)
-
-// SPDX-License-Identifier: BSL-1.0
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
-
-#include <catch2/internal/catch_context.hpp>
-#include <catch2/internal/catch_enforce.hpp>
-#include <catch2/internal/catch_test_case_registry_impl.hpp>
-#include <catch2/internal/catch_reporter_registry.hpp>
-#include <catch2/internal/catch_exception_translator_registry.hpp>
-#include <catch2/internal/catch_tag_alias_registry.hpp>
-#include <catch2/internal/catch_startup_exception_registry.hpp>
-#include <catch2/internal/catch_singletons.hpp>
-#include <catch2/internal/catch_enum_values_registry.hpp>
-#include <catch2/catch_test_case_info.hpp>
-#include <catch2/internal/catch_noncopyable.hpp>
-#include <catch2/interfaces/catch_interfaces_reporter_factory.hpp>
-#include <catch2/internal/catch_move_and_forward.hpp>
-#include <catch2/internal/catch_reporter_registry.hpp>
-
-namespace Catch {
-
-    namespace {
-
-        class RegistryHub : public IRegistryHub,
-                            public IMutableRegistryHub,
-                            private Detail::NonCopyable {
-
-        public: // IRegistryHub
-            RegistryHub() = default;
-            ReporterRegistry const& getReporterRegistry() const override {
-                return m_reporterRegistry;
-            }
-            TestCaseRegistry const& getTestCaseRegistry() const override {
-                return m_testCaseRegistry;
-            }
-            ExceptionTranslatorRegistry const& getExceptionTranslatorRegistry() const override {
-                return m_exceptionTranslatorRegistry;
-            }
-            TagAliasRegistry const& getTagAliasRegistry() const override {
-                return m_tagAliasRegistry;
-            }
-            StartupExceptionRegistry const& getStartupExceptionRegistry() const override {
-                return m_exceptionRegistry;
-            }
-
-        public: // IMutableRegistryHub
-            void registerReporter( std::string const& name, IReporterFactoryPtr factory ) override {
-                m_reporterRegistry.registerReporter( name, CATCH_MOVE(factory) );
-            }
-            void registerListener( Detail::unique_ptr<EventListenerFactory> factory ) override {
-                m_reporterRegistry.registerListener( CATCH_MOVE(factory) );
-            }
-            void registerTest( Detail::unique_ptr<TestCaseInfo>&& testInfo, Detail::unique_ptr<ITestInvoker>&& invoker ) override {
-                m_testCaseRegistry.registerTest( CATCH_MOVE(testInfo), CATCH_MOVE(invoker) );
-            }
-            void registerTranslator( Detail::unique_ptr<IExceptionTranslator>&& translator ) override {
-                m_exceptionTranslatorRegistry.registerTranslator( CATCH_MOVE(translator) );
-            }
-            void registerTagAlias( std::string const& alias, std::string const& tag, SourceLineInfo const& lineInfo ) override {
-                m_tagAliasRegistry.add( alias, tag, lineInfo );
-            }
-            void registerStartupException() noexcept override {
-#if !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
-                m_exceptionRegistry.add(std::current_exception());
-#else
-                CATCH_INTERNAL_ERROR("Attempted to register active exception under CATCH_CONFIG_DISABLE_EXCEPTIONS!");
-#endif
-            }
-            EnumValuesRegistry& getMutableEnumValuesRegistry() override {
-                return m_enumValuesRegistry;
-            }
-
-        private:
-            TestCaseRegistry m_testCaseRegistry;
-            ReporterRegistry m_reporterRegistry;
-            ExceptionTranslatorRegistry m_exceptionTranslatorRegistry;
-            TagAliasRegistry m_tagAliasRegistry;
-            StartupExceptionRegistry m_exceptionRegistry;
-            EnumValuesRegistry m_enumValuesRegistry;
-        };
-    }
-
-    using RegistryHubSingleton = Singleton<RegistryHub, IRegistryHub, IMutableRegistryHub>;
-
-    IRegistryHub const& getRegistryHub() {
-        return RegistryHubSingleton::get();
-    }
-    IMutableRegistryHub& getMutableRegistryHub() {
-        return RegistryHubSingleton::getMutable();
-    }
-    void cleanUp() {
-        cleanupSingletons();
-        cleanUpContext();
-    }
-    std::string translateActiveException() {
-        return getRegistryHub().getExceptionTranslatorRegistry().translateActiveException();
-    }
-
-
-} // end namespace Catch
diff --git a/src/catch2/catch_tag_alias_autoregistrar.cpp b/src/catch2/catch_tag_alias_autoregistrar.cpp
index 9b6633a2..f1c488ec 100644
--- a/src/catch2/catch_tag_alias_autoregistrar.cpp
+++ b/src/catch2/catch_tag_alias_autoregistrar.cpp
@@ -8,7 +8,7 @@
 
 #include <catch2/catch_tag_alias_autoregistrar.hpp>
 #include <catch2/internal/catch_compiler_capabilities.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 
 namespace Catch {
 
diff --git a/src/catch2/catch_tostring.hpp b/src/catch2/catch_tostring.hpp
index c95be44c..9425fb47 100644
--- a/src/catch2/catch_tostring.hpp
+++ b/src/catch2/catch_tostring.hpp
@@ -648,7 +648,7 @@ struct ratio_string<std::milli> {
     };
 }
 
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 
 #define INTERNAL_CATCH_REGISTER_ENUM( enumName, ... ) \
 namespace Catch { \
diff --git a/src/catch2/catch_translate_exception.cpp b/src/catch2/catch_translate_exception.cpp
index c4b28944..dc60174c 100644
--- a/src/catch2/catch_translate_exception.cpp
+++ b/src/catch2/catch_translate_exception.cpp
@@ -7,7 +7,7 @@
 // SPDX-License-Identifier: BSL-1.0
 
 #include <catch2/catch_translate_exception.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 
 namespace Catch {
     namespace Detail {
diff --git a/src/catch2/interfaces/catch_interfaces_all.hpp b/src/catch2/interfaces/catch_interfaces_all.hpp
index b1b8e48a..8ee9dcea 100644
--- a/src/catch2/interfaces/catch_interfaces_all.hpp
+++ b/src/catch2/interfaces/catch_interfaces_all.hpp
@@ -26,7 +26,6 @@
 #include <catch2/interfaces/catch_interfaces_config.hpp>
 #include <catch2/interfaces/catch_interfaces_exception.hpp>
 #include <catch2/interfaces/catch_interfaces_generatortracker.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
 #include <catch2/interfaces/catch_interfaces_reporter.hpp>
 #include <catch2/interfaces/catch_interfaces_reporter_factory.hpp>
 #include <catch2/interfaces/catch_interfaces_testcase.hpp>
diff --git a/src/catch2/interfaces/catch_interfaces_registry_hub.cpp b/src/catch2/interfaces/catch_interfaces_registry_hub.cpp
deleted file mode 100644
index cd688a44..00000000
--- a/src/catch2/interfaces/catch_interfaces_registry_hub.cpp
+++ /dev/null
@@ -1,14 +0,0 @@
-
-//              Copyright Catch2 Authors
-// Distributed under the Boost Software License, Version 1.0.
-//   (See accompanying file LICENSE.txt or copy at
-//        https://www.boost.org/LICENSE_1_0.txt)
-
-// SPDX-License-Identifier: BSL-1.0
-
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
-
-namespace Catch {
-    IRegistryHub::~IRegistryHub() = default;
-    IMutableRegistryHub::~IMutableRegistryHub() = default;
-}
diff --git a/src/catch2/interfaces/catch_interfaces_registry_hub.hpp b/src/catch2/interfaces/catch_interfaces_registry_hub.hpp
deleted file mode 100644
index 14a935fa..00000000
--- a/src/catch2/interfaces/catch_interfaces_registry_hub.hpp
+++ /dev/null
@@ -1,66 +0,0 @@
-
-//              Copyright Catch2 Authors
-// Distributed under the Boost Software License, Version 1.0.
-//   (See accompanying file LICENSE.txt or copy at
-//        https://www.boost.org/LICENSE_1_0.txt)
-
-// SPDX-License-Identifier: BSL-1.0
-#ifndef CATCH_INTERFACES_REGISTRY_HUB_HPP_INCLUDED
-#define CATCH_INTERFACES_REGISTRY_HUB_HPP_INCLUDED
-
-#include <catch2/internal/catch_unique_ptr.hpp>
-
-#include <string>
-
-namespace Catch {
-
-    class TestCaseHandle;
-    struct TestCaseInfo;
-    class TestCaseRegistry;
-    class ExceptionTranslatorRegistry;
-    class IExceptionTranslator;
-    class ReporterRegistry;
-    class IReporterFactory;
-    class TagAliasRegistry;
-    class ITestInvoker;
-    class EnumValuesRegistry;
-    struct SourceLineInfo;
-
-    class StartupExceptionRegistry;
-    class EventListenerFactory;
-
-    using IReporterFactoryPtr = Detail::unique_ptr<IReporterFactory>;
-
-    class IRegistryHub {
-    public:
-        virtual ~IRegistryHub(); // = default
-
-        virtual ReporterRegistry const& getReporterRegistry() const = 0;
-        virtual TestCaseRegistry const& getTestCaseRegistry() const = 0;
-        virtual TagAliasRegistry const& getTagAliasRegistry() const = 0;
-        virtual ExceptionTranslatorRegistry const& getExceptionTranslatorRegistry() const = 0;
-
-
-        virtual StartupExceptionRegistry const& getStartupExceptionRegistry() const = 0;
-    };
-
-    class IMutableRegistryHub {
-    public:
-        virtual ~IMutableRegistryHub(); // = default
-        virtual void registerReporter( std::string const& name, IReporterFactoryPtr factory ) = 0;
-        virtual void registerListener( Detail::unique_ptr<EventListenerFactory> factory ) = 0;
-        virtual void registerTest(Detail::unique_ptr<TestCaseInfo>&& testInfo, Detail::unique_ptr<ITestInvoker>&& invoker) = 0;
-        virtual void registerTranslator( Detail::unique_ptr<IExceptionTranslator>&& translator ) = 0;
-        virtual void registerTagAlias( std::string const& alias, std::string const& tag, SourceLineInfo const& lineInfo ) = 0;
-        virtual void registerStartupException() noexcept = 0;
-        virtual EnumValuesRegistry& getMutableEnumValuesRegistry() = 0;
-    };
-
-    IRegistryHub const& getRegistryHub();
-    IMutableRegistryHub& getMutableRegistryHub();
-    void cleanUp();
-    std::string translateActiveException();
-
-}
-
-#endif // CATCH_INTERFACES_REGISTRY_HUB_HPP_INCLUDED
diff --git a/src/catch2/internal/catch_assertion_handler.cpp b/src/catch2/internal/catch_assertion_handler.cpp
index c28b6190..99ddb11e 100644
--- a/src/catch2/internal/catch_assertion_handler.cpp
+++ b/src/catch2/internal/catch_assertion_handler.cpp
@@ -11,7 +11,7 @@
 #include <catch2/internal/catch_enforce.hpp>
 #include <catch2/internal/catch_debugger.hpp>
 #include <catch2/internal/catch_test_failure_exception.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/internal/catch_run_context.hpp>
 #include <catch2/matchers/catch_matchers_string.hpp>
 
diff --git a/src/catch2/internal/catch_commandline.cpp b/src/catch2/internal/catch_commandline.cpp
index 4ac1847b..2f2be55a 100644
--- a/src/catch2/internal/catch_commandline.cpp
+++ b/src/catch2/internal/catch_commandline.cpp
@@ -9,7 +9,7 @@
 
 #include <catch2/catch_config.hpp>
 #include <catch2/internal/catch_string_manip.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/internal/catch_reporter_registry.hpp>
 #include <catch2/internal/catch_console_colour.hpp>
 #include <catch2/internal/catch_parse_numbers.hpp>
diff --git a/src/catch2/internal/catch_leak_detector.cpp b/src/catch2/internal/catch_leak_detector.cpp
index 7389eaf7..447025a0 100644
--- a/src/catch2/internal/catch_leak_detector.cpp
+++ b/src/catch2/internal/catch_leak_detector.cpp
@@ -7,7 +7,7 @@
 // SPDX-License-Identifier: BSL-1.0
 
 #include <catch2/internal/catch_leak_detector.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/catch_user_config.hpp>
 
 #ifdef CATCH_CONFIG_WINDOWS_CRTDBG
diff --git a/src/catch2/internal/catch_list.cpp b/src/catch2/internal/catch_list.cpp
index 87ace395..2c8ea89c 100644
--- a/src/catch2/internal/catch_list.cpp
+++ b/src/catch2/internal/catch_list.cpp
@@ -7,7 +7,7 @@
 // SPDX-License-Identifier: BSL-1.0
 #include <catch2/internal/catch_list.hpp>
 
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/interfaces/catch_interfaces_reporter.hpp>
 #include <catch2/interfaces/catch_interfaces_testcase.hpp>
 #include <catch2/interfaces/catch_interfaces_reporter_factory.hpp>
diff --git a/src/catch2/internal/catch_registry_hub.cpp b/src/catch2/internal/catch_registry_hub.cpp
new file mode 100644
index 00000000..cf0cac42
--- /dev/null
+++ b/src/catch2/internal/catch_registry_hub.cpp
@@ -0,0 +1,114 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+#include <catch2/internal/catch_registry_hub.hpp>
+
+#include <catch2/internal/catch_context.hpp>
+#include <catch2/internal/catch_enforce.hpp>
+#include <catch2/internal/catch_test_case_registry_impl.hpp>
+#include <catch2/internal/catch_reporter_registry.hpp>
+#include <catch2/internal/catch_exception_translator_registry.hpp>
+#include <catch2/internal/catch_tag_alias_registry.hpp>
+#include <catch2/internal/catch_startup_exception_registry.hpp>
+#include <catch2/internal/catch_singletons.hpp>
+#include <catch2/internal/catch_enum_values_registry.hpp>
+#include <catch2/catch_test_case_info.hpp>
+#include <catch2/internal/catch_noncopyable.hpp>
+#include <catch2/interfaces/catch_interfaces_reporter_factory.hpp>
+#include <catch2/internal/catch_move_and_forward.hpp>
+#include <catch2/internal/catch_reporter_registry.hpp>
+
+namespace Catch {
+
+    struct RegistryHub::RegistryHubImpl {
+        TestCaseRegistry testCaseRegistry;
+        ReporterRegistry reporterRegistry;
+        ExceptionTranslatorRegistry exceptionTranslatorRegistry;
+        TagAliasRegistry tagAliasRegistry;
+        StartupExceptionRegistry exceptionRegistry;
+        EnumValuesRegistry enumValuesRegistry;
+    };
+
+    RegistryHub::RegistryHub():
+        m_impl( Detail::make_unique<RegistryHubImpl>() ) {}
+    RegistryHub::~RegistryHub() = default;
+
+    ReporterRegistry const&
+    RegistryHub::getReporterRegistry() const {
+        return m_impl->reporterRegistry;
+    }
+    TestCaseRegistry const&
+    RegistryHub::getTestCaseRegistry() const {
+        return m_impl->testCaseRegistry;
+    }
+    ExceptionTranslatorRegistry const&
+    RegistryHub::getExceptionTranslatorRegistry() const {
+        return m_impl->exceptionTranslatorRegistry;
+    }
+    TagAliasRegistry const&
+    RegistryHub::getTagAliasRegistry() const {
+        return m_impl->tagAliasRegistry;
+    }
+    StartupExceptionRegistry const&
+    RegistryHub::getStartupExceptionRegistry() const {
+        return m_impl->exceptionRegistry;
+    }
+    void
+    RegistryHub::registerReporter( std::string const& name,
+                           IReporterFactoryPtr factory ) {
+        m_impl->reporterRegistry.registerReporter( name, CATCH_MOVE( factory ) );
+    }
+    void RegistryHub::registerListener(
+        Detail::unique_ptr<EventListenerFactory> factory ) {
+        m_impl->reporterRegistry.registerListener( CATCH_MOVE( factory ) );
+    }
+    void RegistryHub::registerTest(
+        Detail::unique_ptr<TestCaseInfo>&& testInfo,
+                       Detail::unique_ptr<ITestInvoker>&& invoker ) {
+        m_impl->testCaseRegistry.registerTest( CATCH_MOVE( testInfo ),
+                                         CATCH_MOVE( invoker ) );
+    }
+    void RegistryHub::registerTranslator(
+        Detail::unique_ptr<IExceptionTranslator>&& translator ) {
+        m_impl->exceptionTranslatorRegistry.registerTranslator(
+            CATCH_MOVE( translator ) );
+    }
+    void RegistryHub::registerTagAlias( std::string const& alias,
+                           std::string const& tag,
+                           SourceLineInfo const& lineInfo ) {
+        m_impl->tagAliasRegistry.add( alias, tag, lineInfo );
+    }
+    void RegistryHub::registerStartupException() noexcept {
+#if !defined( CATCH_CONFIG_DISABLE_EXCEPTIONS )
+        m_impl->exceptionRegistry.add( std::current_exception() );
+#else
+        CATCH_INTERNAL_ERROR( "Attempted to register active exception under "
+                              "CATCH_CONFIG_DISABLE_EXCEPTIONS!" );
+#endif
+    }
+    EnumValuesRegistry& RegistryHub::getMutableEnumValuesRegistry() {
+        return m_impl->enumValuesRegistry;
+    }
+
+    using RegistryHubSingleton = Singleton<RegistryHub>;
+
+    RegistryHub const& getRegistryHub() {
+        return RegistryHubSingleton::get();
+    }
+    RegistryHub& getMutableRegistryHub() {
+        return RegistryHubSingleton::getMutable();
+    }
+    void cleanUp() {
+        cleanupSingletons();
+        cleanUpContext();
+    }
+    std::string translateActiveException() {
+        return getRegistryHub().getExceptionTranslatorRegistry().translateActiveException();
+    }
+
+
+} // end namespace Catch
diff --git a/src/catch2/internal/catch_registry_hub.hpp b/src/catch2/internal/catch_registry_hub.hpp
new file mode 100644
index 00000000..b13f4aad
--- /dev/null
+++ b/src/catch2/internal/catch_registry_hub.hpp
@@ -0,0 +1,67 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+#ifndef CATCH_REGISTRY_HUB_HPP_INCLUDED
+#define CATCH_REGISTRY_HUB_HPP_INCLUDED
+
+#include <catch2/internal/catch_unique_ptr.hpp>
+
+#include <string>
+
+namespace Catch {
+
+    class TestCaseHandle;
+    struct TestCaseInfo;
+    class TestCaseRegistry;
+    class ExceptionTranslatorRegistry;
+    class IExceptionTranslator;
+    class ReporterRegistry;
+    class IReporterFactory;
+    class TagAliasRegistry;
+    class ITestInvoker;
+    class EnumValuesRegistry;
+    struct SourceLineInfo;
+
+    class StartupExceptionRegistry;
+    class EventListenerFactory;
+
+    using IReporterFactoryPtr = Detail::unique_ptr<IReporterFactory>;
+
+    class RegistryHub {
+        struct RegistryHubImpl;
+        Detail::unique_ptr<RegistryHubImpl> m_impl;
+    public:
+        RegistryHub();
+        ~RegistryHub();
+
+        ReporterRegistry const& getReporterRegistry() const;
+        TestCaseRegistry const& getTestCaseRegistry() const;
+        TagAliasRegistry const& getTagAliasRegistry() const;
+        ExceptionTranslatorRegistry const& getExceptionTranslatorRegistry() const;
+        StartupExceptionRegistry const& getStartupExceptionRegistry() const;
+
+        void registerReporter( std::string const& name,
+                               IReporterFactoryPtr factory );
+        void registerListener( Detail::unique_ptr<EventListenerFactory> factory );
+        void registerTest( Detail::unique_ptr<TestCaseInfo>&& testInfo,
+                           Detail::unique_ptr<ITestInvoker>&& invoker );
+        void registerTranslator( Detail::unique_ptr<IExceptionTranslator>&& translator );
+        void registerTagAlias( std::string const& alias,
+                               std::string const& tag,
+                               SourceLineInfo const& lineInfo );
+        void registerStartupException() noexcept;
+        EnumValuesRegistry& getMutableEnumValuesRegistry();
+    };
+
+    RegistryHub const& getRegistryHub();
+    RegistryHub& getMutableRegistryHub();
+    void cleanUp();
+    std::string translateActiveException();
+
+}
+
+#endif // CATCH_REGISTRY_HUB_HPP_INCLUDED
diff --git a/src/catch2/internal/catch_tag_alias_registry.cpp b/src/catch2/internal/catch_tag_alias_registry.cpp
index f73f4799..fa3fce07 100644
--- a/src/catch2/internal/catch_tag_alias_registry.cpp
+++ b/src/catch2/internal/catch_tag_alias_registry.cpp
@@ -8,7 +8,7 @@
 #include <catch2/internal/catch_tag_alias_registry.hpp>
 #include <catch2/internal/catch_console_colour.hpp>
 #include <catch2/internal/catch_enforce.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/internal/catch_string_manip.hpp>
 
 #include <map>
diff --git a/src/catch2/internal/catch_test_case_registry_impl.cpp b/src/catch2/internal/catch_test_case_registry_impl.cpp
index e806ea6e..4a9cb060 100644
--- a/src/catch2/internal/catch_test_case_registry_impl.cpp
+++ b/src/catch2/internal/catch_test_case_registry_impl.cpp
@@ -10,7 +10,7 @@
 #include <catch2/internal/catch_context.hpp>
 #include <catch2/internal/catch_enforce.hpp>
 #include <catch2/interfaces/catch_interfaces_config.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/internal/catch_random_number_generator.hpp>
 #include <catch2/internal/catch_run_context.hpp>
 #include <catch2/internal/catch_sharding.hpp>
diff --git a/src/catch2/internal/catch_test_registry.cpp b/src/catch2/internal/catch_test_registry.cpp
index b798fb60..0be82bed 100644
--- a/src/catch2/internal/catch_test_registry.cpp
+++ b/src/catch2/internal/catch_test_registry.cpp
@@ -8,7 +8,7 @@
 #include <catch2/internal/catch_test_registry.hpp>
 #include <catch2/internal/catch_compiler_capabilities.hpp>
 #include <catch2/catch_test_case_info.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/internal/catch_string_manip.hpp>
 #include <catch2/internal/catch_move_and_forward.hpp>
 
diff --git a/src/catch2/matchers/internal/catch_matchers_impl.cpp b/src/catch2/matchers/internal/catch_matchers_impl.cpp
index 41b462e5..1e06ff11 100644
--- a/src/catch2/matchers/internal/catch_matchers_impl.cpp
+++ b/src/catch2/matchers/internal/catch_matchers_impl.cpp
@@ -8,7 +8,7 @@
 
 #include <catch2/matchers/internal/catch_matchers_impl.hpp>
 #include <catch2/matchers/catch_matchers.hpp>
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 #include <catch2/internal/catch_move_and_forward.hpp>
 
 namespace Catch {
diff --git a/src/catch2/meson.build b/src/catch2/meson.build
index c3505d10..9b84f79a 100644
--- a/src/catch2/meson.build
+++ b/src/catch2/meson.build
@@ -60,7 +60,6 @@ internal_headers = [
   'interfaces/catch_interfaces_config.hpp',
   'interfaces/catch_interfaces_exception.hpp',
   'interfaces/catch_interfaces_generatortracker.hpp',
-  'interfaces/catch_interfaces_registry_hub.hpp',
   'interfaces/catch_interfaces_reporter.hpp',
   'interfaces/catch_interfaces_reporter_factory.hpp',
   'interfaces/catch_interfaces_testcase.hpp',
@@ -183,7 +182,6 @@ internal_sources = files(
   'interfaces/catch_interfaces_config.cpp',
   'interfaces/catch_interfaces_exception.cpp',
   'interfaces/catch_interfaces_generatortracker.cpp',
-  'interfaces/catch_interfaces_registry_hub.cpp',
   'interfaces/catch_interfaces_reporter.cpp',
   'interfaces/catch_interfaces_reporter_factory.cpp',
   'interfaces/catch_interfaces_testcase.cpp',
@@ -213,6 +211,7 @@ internal_sources = files(
   'internal/catch_polyfills.cpp',
   'internal/catch_random_number_generator.cpp',
   'internal/catch_random_seed_generation.cpp',
+  'internal/catch_registry_hub.cpp',
   'internal/catch_reporter_registry.cpp',
   'internal/catch_reporter_spec_parser.cpp',
   'internal/catch_result_type.cpp',
@@ -250,7 +249,6 @@ internal_sources = files(
   'catch_config.cpp',
   'catch_get_random_seed.cpp',
   'catch_message.cpp',
-  'catch_registry_hub.cpp',
   'catch_session.cpp',
   'catch_tag_alias_autoregistrar.cpp',
   'catch_test_case_info.cpp',
diff --git a/src/catch2/reporters/catch_reporter_registrars.cpp b/src/catch2/reporters/catch_reporter_registrars.cpp
index 17f59517..9bf89805 100644
--- a/src/catch2/reporters/catch_reporter_registrars.cpp
+++ b/src/catch2/reporters/catch_reporter_registrars.cpp
@@ -9,6 +9,7 @@
 #include <catch2/reporters/catch_reporter_registrars.hpp>
 
 #include <catch2/internal/catch_compiler_capabilities.hpp>
+#include <catch2/internal/catch_registry_hub.hpp>
 
 namespace Catch {
     namespace Detail {
diff --git a/src/catch2/reporters/catch_reporter_registrars.hpp b/src/catch2/reporters/catch_reporter_registrars.hpp
index cab395f4..daaeef03 100644
--- a/src/catch2/reporters/catch_reporter_registrars.hpp
+++ b/src/catch2/reporters/catch_reporter_registrars.hpp
@@ -8,7 +8,6 @@
 #ifndef CATCH_REPORTER_REGISTRARS_HPP_INCLUDED
 #define CATCH_REPORTER_REGISTRARS_HPP_INCLUDED
 
-#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
 #include <catch2/interfaces/catch_interfaces_reporter.hpp>
 #include <catch2/interfaces/catch_interfaces_reporter_factory.hpp>
 #include <catch2/internal/catch_compiler_capabilities.hpp>