diff --git a/extensions/venkman/resources/content/venkman-prefs.js b/extensions/venkman/resources/content/venkman-prefs.js
index 422216e4755c..f299ac0731cc 100644
--- a/extensions/venkman/resources/content/venkman-prefs.js
+++ b/extensions/venkman/resources/content/venkman-prefs.js
@@ -40,6 +40,7 @@ function initPrefs()
     console.prefs = new Object();
 
     //    console.addPref ("input.commandchar", "/");    
+    console.addPref ("sourcetext.tab.string", "    ");
     console.addPref ("input.history.max", 20);
     console.addPref ("input.dtab.time", 500);
     console.addPref ("output.wordbreak.length", 40);