diff --git a/erpnext/config/docs.py b/erpnext/config/docs.py
index 9c9c4c7..82cb1fb 100644
--- a/erpnext/config/docs.py
+++ b/erpnext/config/docs.py
@@ -23,5 +23,5 @@
 	context.top_bar_items = [
 		{"label": "User Manual", "url": context.docs_base_url + "/user/manual", "right": 1},
 		{"label": "Videos", "url": context.docs_base_url + "/user/videos", "right": 1},
-		{"label": "Developer Docs", "url": context.docs_base_url + "/current", "right": 1}
+		{"label": "API Documentation", "url": context.docs_base_url + "/current", "right": 1}
 	]
diff --git a/erpnext/controllers/sales_and_purchase_return.py b/erpnext/controllers/sales_and_purchase_return.py
index 9e0dee8..ac8a5df 100644
--- a/erpnext/controllers/sales_and_purchase_return.py
+++ b/erpnext/controllers/sales_and_purchase_return.py
@@ -67,6 +67,9 @@
 
 	already_returned_items = get_already_returned_items(doc)
 
+	# ( not mandatory when it is Purchase Invoice or a Sales Invoice without Update Stock )
+	warehouse_mandatory = not (doc.doctype=="Purchase Invoice" or (doc.doctype=="Sales Invoice" and not doc.update_stock))
+
 	items_returned = False
 	for d in doc.get("items"):
 		if flt(d.qty) < 0:
@@ -96,8 +99,8 @@
 							if s not in ref_serial_nos:
 								frappe.throw(_("Row # {0}: Serial No {1} does not match with {2} {3}")
 									.format(d.idx, s, doc.doctype, doc.return_against))
-									
-				if doc.doctype != "Purchase Invoice" and not d.get("warehouse"):
+
+				if warehouse_mandatory and not d.get("warehouse"):
 					frappe.throw(_("Warehouse is mandatory"))
 
 			items_returned = True