diff --git a/gclc/src/main/java/net/bigeon/gclc/ConsoleApplication.java b/gclc/src/main/java/net/bigeon/gclc/ConsoleApplication.java
index e963e55..0f636ed 100644
--- a/gclc/src/main/java/net/bigeon/gclc/ConsoleApplication.java
+++ b/gclc/src/main/java/net/bigeon/gclc/ConsoleApplication.java
@@ -71,9 +71,10 @@ package net.bigeon.gclc;
  */
 import java.io.IOException;
 import java.io.InterruptedIOException;
-import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -125,7 +126,7 @@ public final class ConsoleApplication implements ICommandProvider {
     /** The state of this application. */
     private boolean                            running;
     /** The listeners. */
-    private final List<CommandRequestListener> listeners = new ArrayList<>();
+    private final Set<CommandRequestListener> listeners = new LinkedHashSet<>();
 
     /** Create a console application.
      *
@@ -188,9 +189,9 @@ public final class ConsoleApplication implements ICommandProvider {
         List<String> args;
         try {
             args = GCLCConstants.splitCommand(cmd);
-        } catch (final CommandParsingException e1) {
+        } catch (final CommandParsingException e) {
             out.println("Command line cannot be parsed"); //$NON-NLS-1$
-            LOGGER.log(Level.FINE, "Invalid user command " + cmd, e1); //$NON-NLS-1$
+            LOGGER.log(Level.FINE, "Invalid user command " + cmd, e); //$NON-NLS-1$
             return;
         }
         if (!args.isEmpty()) {