diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index 2490deaa2fc5..969ee5e48557 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -215,6 +215,7 @@ pref("browser.search.basic.min_ver", "0.0");
 
 pref("browser.history.grouping", "day");
 pref("browser.sessionhistory.max_entries", 50);
+pref("browser.sessionhistory.max_viewers", 3);
 
 // handle external links
 // 0=default window, 1=current window/tab, 2=new window, 3=new tab in most recent window
diff --git a/xpfe/bootstrap/browser-prefs.js b/xpfe/bootstrap/browser-prefs.js
index efc8a32ed211..4cafeca8f600 100644
--- a/xpfe/bootstrap/browser-prefs.js
+++ b/xpfe/bootstrap/browser-prefs.js
@@ -111,6 +111,7 @@ pref("browser.search.param.Google.1.default", "chrome://navigator/content/search
 
 pref("browser.history.grouping", "day");
 pref("browser.sessionhistory.max_entries", 50);
+pref("browser.sessionhistory.max_viewers", 3);
 
 // Tabbed browser
 pref("browser.tabs.loadDivertedInBackground", false);