diff -r 5714fc2292e2 move.py
--- a/trytond/trytond/modules/stock/move.py	Wed Nov 08 00:00:54 2017 +0100
+++ b/trytond/trytond/modules/stock/move.py	Wed Nov 22 00:59:58 2017 +0100
@@ -18,6 +18,7 @@
 from trytond.tools import reduce_ids
 from trytond.transaction import Transaction
 from trytond.pool import Pool
+from collections import defaultdict
 
 from trytond.modules.product import price_digits
 
@@ -1136,18 +1137,25 @@
 
         product_getter = operator.itemgetter(grouping.index('product') + 1)
         res_product_ids = set()
-        quantities = {}
+        quantities = defaultdict(lambda: 0)
         keys = set()
+        # We can do a quick loop without propagation if the request is for a
+        # single location because all the locations are children and we can sum
+        # them directly.
+        if len(location_ids) == 1:
+            location, = location_ids
+
         for line in raw_lines:
-            location = line[0]
+            if len(location_ids) > 1:
+                location = line[0]
             key = tuple(line[1:-1])
             quantity = line[-1]
-            quantities[(location,) + key] = quantity
+            quantities[(location,) + key] += quantity
             res_product_ids.add(product_getter(line))
             keys.add(key)
 
         # Propagate quantities on from child locations to their parents
-        if with_childs:
+        if with_childs and len(location_ids) > 1:
             # Fetch all child locations
             locations = Location.search([
                     ('parent', 'child_of', location_ids),
@@ -1186,9 +1194,28 @@
                 if location not in location_ids:
                     del quantities[key]
 
+        Product = Pool().get('product.product')
+        Template = Pool().get('product.template')
+        Uom = Pool().get('product.uom')
+
         # Round quantities
-        default_uom = dict((p.id, p.default_uom) for p in
-            Product.browse(list(res_product_ids)))
+        product = Product.__table__()
+        template = Template.__table__()
+
+        cursor = Transaction().cursor
+
+        cursor.execute(*template.join(product,
+            condition=product.template == template.id).select(
+                product.id, template.default_uom,
+                where=reduce_ids(product.id, list(res_product_ids))))
+
+        default_uom = {}
+        for product in res_product_ids:
+            default_uom[product] = {}
+
+        for product, duom in cursor.fetchall():
+            default_uom[product] = Uom(duom)
+
         for key, quantity in quantities.iteritems():
             location = key[0]
             product = product_getter(key)