diff --git a/src/main/scala/ij_plugins/imagej_launcher/Logger.scala b/src/main/scala/ij_plugins/imagej_launcher/Logger.scala
index 743169e..baa5390 100644
--- a/src/main/scala/ij_plugins/imagej_launcher/Logger.scala
+++ b/src/main/scala/ij_plugins/imagej_launcher/Logger.scala
@@ -7,17 +7,13 @@ package ij_plugins.imagej_launcher
 
 import ij_plugins.imagej_launcher.Logger.Level
 
-class Logger:
-
-  var level: Level = Level.Info
-
+class Logger(val level: Level = Level.Info):
   def debug(msg: String): Unit = pprint(Level.Debug, msg)
   def info(msg: String): Unit  = pprint(Level.Info, msg)
+  def error(msg: String): Unit = pprint(Level.Error, msg)
 
   private def pprint(l: Level, message: String): Unit =
-    if l.level <= level.level then println(s"${l.name}: $message")
-
-  def error(msg: String): Unit = pprint(Level.Error, msg)
+    if l.level <= level.level then println(f"${l.name}%-5s: $message")
 
 object Logger:
   enum Level(val level: Int, val name: String):
diff --git a/src/main/scala/ij_plugins/imagej_launcher/Main.scala b/src/main/scala/ij_plugins/imagej_launcher/Main.scala
index 95038f1..de4000e 100644
--- a/src/main/scala/ij_plugins/imagej_launcher/Main.scala
+++ b/src/main/scala/ij_plugins/imagej_launcher/Main.scala
@@ -10,7 +10,7 @@ import scopt.{DefaultOEffectSetup, OParser}
 import java.io.File
 
 object Main:
-  private val logger  = new Logger()
+  private var logger  = new Logger()
   private val AppName = "ijp-imagej-launcher"
   //  private val AppVersion = s"${Version.version} [${Version.buildTimeStr}]"
   private val AppVersion     = s"0.1.0"
@@ -71,7 +71,7 @@ object Main:
     OParser.parse(parser1, args, Config())
   end parseCommandLine
 
-  private def setupLogger(logLevel: Logger.Level): Unit = logger.level = logLevel
+  private def setupLogger(logLevel: Logger.Level): Unit = logger = new Logger(logLevel)
 
   private def runLauncher(config: Config): Unit = new Launcher(logger).run(config)