diff --git a/lib/lg2_logger.cpp b/lib/lg2_logger.cpp
index bd1e89d..8d9c034 100644
--- a/lib/lg2_logger.cpp
+++ b/lib/lg2_logger.cpp
@@ -134,7 +134,7 @@
 static void cerr_extra_output(level l, const lg2::source_location& s,
                               const std::string& m)
 {
-    static const char* format = []() {
+    static const char* const defaultFormat = []() {
         const char* f = getenv("LG2_FORMAT");
         if (nullptr == f)
         {
@@ -143,6 +143,8 @@
         return f;
     }();
 
+    const char* format = defaultFormat;
+
     while (*format)
     {
         if (*format != '%')