diff --git a/frappe/patches.txt b/frappe/patches.txt
index 623bad9928..fca6092bdd 100644
--- a/frappe/patches.txt
+++ b/frappe/patches.txt
@@ -28,3 +28,4 @@ frappe.patches.v4_0.deprecate_control_panel
 frappe.patches.v4_0.file_manager_hooks
 execute:frappe.get_doc("User", "Guest").save()
 frappe.patches.v4_0.deprecate_link_selects
+frappe.patches.v4_0.set_language_in_system_settings
diff --git a/frappe/patches/v4_0/set_language_in_system_settings.py b/frappe/patches/v4_0/set_language_in_system_settings.py
new file mode 100644
index 0000000000..162641cd69
--- /dev/null
+++ b/frappe/patches/v4_0/set_language_in_system_settings.py
@@ -0,0 +1,23 @@
+# Copyright (c) 2013, Web Notes Technologies Pvt. Ltd. and Contributors
+# MIT License. See license.txt
+
+from __future__ import unicode_literals
+import frappe
+from collections import Counter
+from frappe.core.doctype.user.user import STANDARD_USERS
+
+def execute():
+	if frappe.db.get_value("System Settings", "System Settings", "language"):
+		return
+
+	# find most common language
+	lang = frappe.db.sql_list("""select language from `tabUser`
+		where ifnull(language, '')!='' and language not like "Loading%%" and name not in ({standard_users})""".format(
+		standard_users=", ".join(["%s"]*len(STANDARD_USERS))), tuple(STANDARD_USERS))
+	lang = Counter(lang).most_common(1)
+	lang = (len(lang) > 0) and lang[0][0] or "english"
+
+	# set language in System Settings
+	system_settings = frappe.get_doc("System Settings")
+	system_settings.language = lang
+	system_settings.save()