diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index f57725a9..93da8c26 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -36,6 +36,7 @@ set(INTERNAL_HEADERS
     ${SOURCES_DIR}/generators/catch_generators_all.hpp
     ${SOURCES_DIR}/interfaces/catch_interfaces_all.hpp
     ${SOURCES_DIR}/matchers/internal/catch_matchers_impl.hpp
+    ${SOURCES_DIR}/internal/catch_case_insensitive_comparisons.hpp
     ${SOURCES_DIR}/internal/catch_console_width.hpp
     ${SOURCES_DIR}/internal/catch_container_nonmembers.hpp
     ${SOURCES_DIR}/internal/catch_noncopyable.hpp
@@ -157,6 +158,7 @@ set(IMPL_SOURCES
     ${SOURCES_DIR}/internal/catch_commandline.cpp
     ${SOURCES_DIR}/internal/catch_source_line_info.cpp
     ${SOURCES_DIR}/catch_config.cpp
+    ${SOURCES_DIR}/internal/catch_case_insensitive_comparisons.cpp
     ${SOURCES_DIR}/internal/catch_console_colour.cpp
     ${SOURCES_DIR}/internal/catch_context.cpp
     ${SOURCES_DIR}/internal/catch_debug_console.cpp
diff --git a/src/catch2/catch_all.hpp b/src/catch2/catch_all.hpp
index 85d8e462..92cdc205 100644
--- a/src/catch2/catch_all.hpp
+++ b/src/catch2/catch_all.hpp
@@ -45,6 +45,7 @@
 #include <catch2/generators/catch_generators_all.hpp>
 #include <catch2/interfaces/catch_interfaces_all.hpp>
 #include <catch2/internal/catch_assertion_handler.hpp>
+#include <catch2/internal/catch_case_insensitive_comparisons.hpp>
 #include <catch2/internal/catch_case_sensitive.hpp>
 #include <catch2/internal/catch_clara.hpp>
 #include <catch2/internal/catch_commandline.hpp>
diff --git a/src/catch2/interfaces/catch_interfaces_combined_tu.cpp b/src/catch2/interfaces/catch_interfaces_combined_tu.cpp
index 0f2f406b..b1ce0928 100644
--- a/src/catch2/interfaces/catch_interfaces_combined_tu.cpp
+++ b/src/catch2/interfaces/catch_interfaces_combined_tu.cpp
@@ -76,21 +76,9 @@ namespace Catch {
 
 
 #include <catch2/interfaces/catch_interfaces_reporter_registry.hpp>
-#include <catch2/internal/catch_string_manip.hpp>
-
-#include <algorithm>
 
 namespace Catch {
-
     IReporterRegistry::~IReporterRegistry() = default;
-    bool IReporterRegistry::CaseInsensitiveCmp::operator()(std::string const& lhs, std::string const& rhs) const {
-        return std::lexicographical_compare(lhs.begin(), lhs.end(),
-                          rhs.begin(), rhs.end(),
-                          [](char l, char r) {
-                              return toLower(l) < toLower(r);
-                          });
-    }
-
 }
 
 
diff --git a/src/catch2/interfaces/catch_interfaces_reporter_registry.hpp b/src/catch2/interfaces/catch_interfaces_reporter_registry.hpp
index 0228f9c3..57c652e7 100644
--- a/src/catch2/interfaces/catch_interfaces_reporter_registry.hpp
+++ b/src/catch2/interfaces/catch_interfaces_reporter_registry.hpp
@@ -8,6 +8,7 @@
 #ifndef CATCH_INTERFACES_REPORTER_REGISTRY_HPP_INCLUDED
 #define CATCH_INTERFACES_REPORTER_REGISTRY_HPP_INCLUDED
 
+#include <catch2/internal/catch_case_insensitive_comparisons.hpp>
 #include <catch2/internal/catch_unique_ptr.hpp>
 
 #include <string>
@@ -24,11 +25,7 @@ namespace Catch {
     using IReporterFactoryPtr = Detail::unique_ptr<IReporterFactory>;
 
     struct IReporterRegistry {
-        struct CaseInsensitiveCmp {
-            bool operator()(std::string const& lhs, std::string const& rhs) const;
-        };
-
-        using FactoryMap = std::map<std::string, IReporterFactoryPtr, CaseInsensitiveCmp>;
+        using FactoryMap = std::map<std::string, IReporterFactoryPtr, Detail::CaseInsensitiveLess>;
         using Listeners = std::vector<IReporterFactoryPtr>;
 
         virtual ~IReporterRegistry(); // = default
diff --git a/src/catch2/internal/catch_case_insensitive_comparisons.cpp b/src/catch2/internal/catch_case_insensitive_comparisons.cpp
new file mode 100644
index 00000000..3081edb3
--- /dev/null
+++ b/src/catch2/internal/catch_case_insensitive_comparisons.cpp
@@ -0,0 +1,26 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE_1_0.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#include <catch2/internal/catch_case_insensitive_comparisons.hpp>
+#include <catch2/internal/catch_string_manip.hpp>
+
+#include <algorithm>
+
+namespace Catch {
+    namespace Detail {
+
+        bool CaseInsensitiveLess::operator()( std::string const& lhs,
+                                              std::string const& rhs ) const {
+            return std::lexicographical_compare(
+                lhs.begin(), lhs.end(),
+                rhs.begin(), rhs.end(),
+                []( char l, char r ) { return toLower( l ) < toLower( r ); } );
+        }
+
+    } // namespace Detail
+} // namespace Catch
diff --git a/src/catch2/internal/catch_case_insensitive_comparisons.hpp b/src/catch2/internal/catch_case_insensitive_comparisons.hpp
new file mode 100644
index 00000000..372809d4
--- /dev/null
+++ b/src/catch2/internal/catch_case_insensitive_comparisons.hpp
@@ -0,0 +1,24 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE_1_0.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+#ifndef CATCH_CASE_INSENSITIVE_COMPARISONS_HPP_INCLUDED
+#define CATCH_CASE_INSENSITIVE_COMPARISONS_HPP_INCLUDED
+
+#include <string>
+
+namespace Catch {
+    namespace Detail {
+        //! Provides case-insensitive `op<` semantics when called
+        struct CaseInsensitiveLess {
+            bool operator()( std::string const& lhs,
+                             std::string const& rhs ) const;
+        };
+
+    } // namespace Detail
+} // namespace Catch
+
+#endif // CATCH_CASE_INSENSITIVE_COMPARISONS_HPP_INCLUDED
\ No newline at end of file