diff --git a/common/content/liberator.js b/common/content/liberator.js
index a26ed8fa..d1d29227 100644
--- a/common/content/liberator.js
+++ b/common/content/liberator.js
@@ -255,7 +255,7 @@ const liberator = (function () //{{{
             "Open a " + config.name + " dialog",
             function (args)
             {
-                let arg = args[0];
+                let arg = args[0].toLowerCase();
 
                 try
                 {
diff --git a/vimperator/NEWS b/vimperator/NEWS
index ee0079c8..75c5d29a 100644
--- a/vimperator/NEWS
+++ b/vimperator/NEWS
@@ -82,6 +82,7 @@
     * stop macro playback on <C-c>
     * :bmark now updates a bookmark, if possible. :bmark! adds a new one
     * many bug fixes
+    * :dialog and :sidebar now doesn't care about case for arguments
 
 2008-08-16:
     * version 1.2
diff --git a/vimperator/content/config.js b/vimperator/content/config.js
index 69cddbbb..13c9c632 100644
--- a/vimperator/content/config.js
+++ b/vimperator/content/config.js
@@ -371,10 +371,10 @@ const config = { //{{{
             "Open the sidebar window",
             function (args)
             {
-                let arg = args.literalArg;
+                let arg = args.literalArg.toLowerCase();
 
                 // focus if the requested sidebar is already open
-                if (document.getElementById("sidebar-title").value == arg)
+                if (document.getElementById("sidebar-title").value.toLowerCase() == arg)
                 {
                     document.getElementById("sidebar-box").focus();
                     return;
@@ -384,7 +384,7 @@ const config = { //{{{
 
                 for (let [,panel] in Iterator(menu.childNodes))
                 {
-                    if (panel.label == arg)
+                    if (panel.label.toLowerCase() == arg)
                     {
                         panel.doCommand();
                         return;