diff --git a/src/catch2/catch_message.cpp b/src/catch2/catch_message.cpp
index adb9b476..1ea8c299 100644
--- a/src/catch2/catch_message.cpp
+++ b/src/catch2/catch_message.cpp
@@ -85,8 +85,8 @@ namespace Catch {
             case ',':
                 if (start != pos && openings.empty()) {
                     m_messages.emplace_back(macroName, lineInfo, resultType);
-                    m_messages.back().message = static_cast<std::string>(trimmed(start, pos));
-                    m_messages.back().message += " := ";
+                    m_messages.back().message += trimmed(start, pos);
+                    m_messages.back().message += " := "_sr;
                     start = pos;
                 }
                 break;
@@ -95,8 +95,8 @@ namespace Catch {
         }
         assert(openings.empty() && "Mismatched openings");
         m_messages.emplace_back(macroName, lineInfo, resultType);
-        m_messages.back().message = static_cast<std::string>(trimmed(start, names.size() - 1));
-        m_messages.back().message += " := ";
+        m_messages.back().message += trimmed(start, names.size() - 1);
+        m_messages.back().message += " := "_sr;
     }
     Capturer::~Capturer() {
         assert( m_captured == m_messages.size() );