diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index 62a1e0c147be..7203c99060c6 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -191,7 +191,6 @@ pref("browser.shell.checkDefaultBrowser", true);
 pref("browser.startup.page",                1);
 pref("browser.startup.homepage",            "resource:/browserconfig.properties");
 
-pref("browser.cache.disk.capacity",         50000);
 pref("browser.enable_automatic_image_resizing", true);
 pref("browser.chrome.site_icons", true);
 pref("browser.chrome.favicons", true);
diff --git a/browser/components/preferences/advanced.js b/browser/components/preferences/advanced.js
index 00b91f9ef46b..29c05c1ca84a 100644
--- a/browser/components/preferences/advanced.js
+++ b/browser/components/preferences/advanced.js
@@ -163,7 +163,7 @@ var gAdvancedPane = {
   readCacheSize: function ()
   {
     var preference = document.getElementById("browser.cache.disk.capacity");
-    return preference.value / 1000;
+    return preference.value / 1024;
   },
 
   /**
@@ -174,7 +174,7 @@ var gAdvancedPane = {
   {
     var cacheSize = document.getElementById("cacheSize");
     var intValue = parseInt(cacheSize.value, 10);
-    return isNaN(intValue) ? 0 : intValue * 1000;
+    return isNaN(intValue) ? 0 : intValue * 1024;
   },
 
   /**