diff --git a/browser/components/nsBrowserGlue.js b/browser/components/nsBrowserGlue.js
index c8610589446e..7b1040a019e8 100644
--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -1831,13 +1831,13 @@ BrowserGlue.prototype = {
       let tabSubstring = gTabbrowserBundle.GetStringFromName("tabs.closeWarningMultipleWindowsTabSnippet");
       tabSubstring = PluralForm.get(pagecount, tabSubstring).replace(/#1/, pagecount);
 
-      let stringID = sessionWillBeRestored ? "tabs.closeWarningMultipleWindowsSessionRestore"
+      let stringID = sessionWillBeRestored ? "tabs.closeWarningMultipleWindowsSessionRestore2"
                                            : "tabs.closeWarningMultipleWindows";
       let windowString = gTabbrowserBundle.GetStringFromName(stringID);
       windowString = PluralForm.get(windowcount, windowString).replace(/#1/, windowcount);
       warningMessage = windowString.replace(/%(?:1\$)?S/i, tabSubstring);
     } else {
-      let stringID = sessionWillBeRestored ? "tabs.closeWarningMultipleSessionRestore"
+      let stringID = sessionWillBeRestored ? "tabs.closeWarningMultipleSessionRestore2"
                                            : "tabs.closeWarningMultiple";
       warningMessage = gTabbrowserBundle.GetStringFromName(stringID);
       warningMessage = PluralForm.get(pagecount, warningMessage).replace("#1", pagecount);
diff --git a/browser/locales/en-US/chrome/browser/tabbrowser.properties b/browser/locales/en-US/chrome/browser/tabbrowser.properties
index 0040f7e56666..5f42b7409e23 100644
--- a/browser/locales/en-US/chrome/browser/tabbrowser.properties
+++ b/browser/locales/en-US/chrome/browser/tabbrowser.properties
@@ -15,12 +15,17 @@ tabs.closeAndQuitTitleTabsWin=Exit and close tabs?
 # The singular form is not considered since this string is used only for
 # multiple tabs.
 tabs.closeWarningMultiple=;You are about to close #1 tabs. Are you sure you want to continue?
-# LOCALIZATION NOTE (tabs.closeWarningMultipleSessionRestore):
+# LOCALIZATION NOTE (tabs.closeWarningMultipleSessionRestore2):
 # Semicolon-separated list of plural forms. See:
 # http://developer.mozilla.org/en/docs/Localization_and_Plurals
-# The singular form is not considered since this string is used only for
-# multiple tabs.
-tabs.closeWarningMultipleSessionRestore=;You are about to close #1 tabs. These tabs will be restored when you restart. Are you sure you want to continue?
+# The forms for 0 or 1 items are not considered since this string is used only
+# for multiple tabs.
+# If
+#   "Tabs in non-private windows will be restored when you restart"
+# is difficult to translate, you could translate
+#   "Tabs (except those in private windows) will be restored when you restart"
+# instead.
+tabs.closeWarningMultipleSessionRestore2=;You are about to close #1 tabs. Tabs in non-private windows will be restored when you restart. Are you sure you want to continue?
 tabs.closeButtonMultiple=Close tabs
 tabs.closeWarningPromptMe=Warn me when I attempt to close multiple tabs
 
@@ -33,15 +38,20 @@ tabs.closeWarningPromptMe=Warn me when I attempt to close multiple tabs
 # of tabs in these windows.
 # Note that every one of these plural forms must contain one instance of '%S'.
 tabs.closeWarningMultipleWindows=;You are about to close #1 windows %S. Are you sure you want to continue?
-# LOCALIZATION NOTE (tabs.closeWarningMultipleWindowsSessionRestore):
+# LOCALIZATION NOTE (tabs.closeWarningMultipleWindowsSessionRestore2):
 # Semicolon-separated list of plural forms. See:
 # http://developer.mozilla.org/en/docs/Localization_and_Plurals
 # The forms for 0 or 1 items are not considered since this string is used only for
 # multiple windows. The %S replacement form will be replaced with the contents
 # of tabs.closeWarningMultipleWindowsTabSnippet, which will contain the number
 # of tabs in these windows.
+# If
+#   "Tabs in non-private windows will be restored when you restart"
+# is difficult to translate, you could translate
+#   "Tabs (except those in private windows) will be restored when you restart"
+# instead.
 # Note that every one of these plural forms must contain one instance of '%S'.
-tabs.closeWarningMultipleWindowsSessionRestore=;You are about to close #1 windows %S. These tabs will be restored when you restart. Are you sure you want to continue?
+tabs.closeWarningMultipleWindowsSessionRestore2=;You are about to close #1 windows %S. Tabs in non-private windows will be restored when you restart. Are you sure you want to continue?
 
 # LOCALIZATION NOTE (tabs.closeWarningMultipleWindowsTabSnippet):
 # Semicolon-separated list of plural forms. See: