diff --git a/src/catch2/internal/catch_case_insensitive_comparisons.cpp b/src/catch2/internal/catch_case_insensitive_comparisons.cpp
index 3081edb3..3f81b219 100644
--- a/src/catch2/internal/catch_case_insensitive_comparisons.cpp
+++ b/src/catch2/internal/catch_case_insensitive_comparisons.cpp
@@ -14,8 +14,8 @@
 namespace Catch {
     namespace Detail {
 
-        bool CaseInsensitiveLess::operator()( std::string const& lhs,
-                                              std::string const& rhs ) const {
+        bool CaseInsensitiveLess::operator()( StringRef lhs,
+                                              StringRef rhs ) const {
             return std::lexicographical_compare(
                 lhs.begin(), lhs.end(),
                 rhs.begin(), rhs.end(),
diff --git a/src/catch2/internal/catch_case_insensitive_comparisons.hpp b/src/catch2/internal/catch_case_insensitive_comparisons.hpp
index 372809d4..6dfe712b 100644
--- a/src/catch2/internal/catch_case_insensitive_comparisons.hpp
+++ b/src/catch2/internal/catch_case_insensitive_comparisons.hpp
@@ -8,14 +8,16 @@
 #ifndef CATCH_CASE_INSENSITIVE_COMPARISONS_HPP_INCLUDED
 #define CATCH_CASE_INSENSITIVE_COMPARISONS_HPP_INCLUDED
 
+#include <catch2/internal/catch_stringref.hpp>
+
 #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;
+            bool operator()( StringRef lhs,
+                             StringRef rhs ) const;
         };
 
     } // namespace Detail