diff --git a/include/internal/catch_decomposer.cpp b/include/internal/catch_decomposer.cpp
index f7da22b5..f8b282dc 100644
--- a/include/internal/catch_decomposer.cpp
+++ b/include/internal/catch_decomposer.cpp
@@ -11,7 +11,7 @@
 
 namespace Catch {
 
-    void formatReconstructedExpression( std::ostream &os, std::string const& lhs, std::string const& op, std::string const& rhs ) {
+    void formatReconstructedExpression( std::ostream &os, std::string const& lhs, StringRef op, std::string const& rhs ) {
         if( lhs.size() + rhs.size() < 40 &&
                 lhs.find('\n') == std::string::npos &&
                 rhs.find('\n') == std::string::npos )
diff --git a/include/internal/catch_decomposer.h b/include/internal/catch_decomposer.h
index c61ca856..48f87f60 100644
--- a/include/internal/catch_decomposer.h
+++ b/include/internal/catch_decomposer.h
@@ -32,13 +32,13 @@ namespace Catch {
         virtual ~ITransientExpression() = default;
     };
 
-    void formatReconstructedExpression( std::ostream &os, std::string const& lhs, std::string const& op, std::string const& rhs );
+    void formatReconstructedExpression( std::ostream &os, std::string const& lhs, StringRef op, std::string const& rhs );
 
     template<typename LhsT, typename RhsT>
     class BinaryExpr  : public ITransientExpression {
         bool m_result;
         LhsT m_lhs;
-        std::string m_op;
+        StringRef m_op;
         RhsT m_rhs;
 
         auto isBinaryExpression() const -> bool override { return true; }