diff --git a/docs/structured-logging.md b/docs/structured-logging.md
index 6801279..b7a4178 100644
--- a/docs/structured-logging.md
+++ b/docs/structured-logging.md
@@ -154,8 +154,20 @@
 
 When running an application or daemon on a console or SSH session, it might
 not be obvious that the application is writing to the journal.  The `lg2` APIs
-detect if the application is running on a TTY and additionally mirror the
-information sent to the journal to the TTY.
+detect if the application is running on a TTY and additionally log to the TTY.
+
+The format of information sent to the TTY can be adjusted by setting the
+desired format string in the `LG2_FORMAT` environment variable.  Supported
+fields are:
+
+- `%%` : a `'%'` literal
+- `%f` : the logging function's name
+- `%F` : the logging function's file
+- `%l` : the log level as an integer
+- `%L` : the logging function's line number
+- `%m` : the lg2 message
+
+The default format is `"<%l> %m"`.
 
 ### Why a new API?
 
diff --git a/lib/lg2_logger.cpp b/lib/lg2_logger.cpp
index c8a0d7f..bd1e89d 100644
--- a/lib/lg2_logger.cpp
+++ b/lib/lg2_logger.cpp
@@ -134,8 +134,64 @@
 static void cerr_extra_output(level l, const lg2::source_location& s,
                               const std::string& m)
 {
-    std::cerr << s.file_name() << ":" << s.line() << ":" << s.function_name()
-              << "|<" << static_cast<uint64_t>(l) << "> " << m << std::endl;
+    static const char* format = []() {
+        const char* f = getenv("LG2_FORMAT");
+        if (nullptr == f)
+        {
+            f = "<%l> %m";
+        }
+        return f;
+    }();
+
+    while (*format)
+    {
+        if (*format != '%')
+        {
+            std::cerr << *format;
+            ++format;
+            continue;
+        }
+
+        ++format;
+        switch (*format)
+        {
+            case '%':
+            case '\0':
+                std::cerr << '%';
+                break;
+
+            case 'f':
+                std::cerr << s.function_name();
+                break;
+
+            case 'F':
+                std::cerr << s.file_name();
+                break;
+
+            case 'l':
+                std::cerr << static_cast<uint64_t>(l);
+                break;
+
+            case 'L':
+                std::cerr << s.line();
+                break;
+
+            case 'm':
+                std::cerr << m;
+                break;
+
+            default:
+                std::cerr << '%' << *format;
+                break;
+        }
+
+        if (*format != '\0')
+        {
+            ++format;
+        }
+    }
+
+    std::cerr << std::endl;
 }
 
 // Use the cerr output method if we are on a TTY.