diff --git a/kfet/views.py b/kfet/views.py
index e81640ba..5e1e560d 100644
--- a/kfet/views.py
+++ b/kfet/views.py
@@ -416,16 +416,19 @@ def kpsul_perform_operations(request):
 
     # 1. Calculating amount of each PURCHASE operations
     # 2. and total amount for operation group
-    # 3. Adding required permissions to perform each operation
+    # 3. Updating (no commit) stock of article for PURCHASE operations
+    # 4. Adding required permissions to perform each operation
     for operation in operations:
-        # 1
         if operation.type == Operation.PURCHASE:
+            # 1
             operation.amount = - operation.article.price * operation.article_nb
             if operationgroup.on_acc.is_cof:
                 operation.amount = operation.amount / cof_grant_divisor
-        # 2
-        operationgroup.amount += operation.amount
+            # 2
+            operation.article.stock -= operation.article_nb
         # 3
+        operationgroup.amount += operation.amount
+        # 4
         if operation.type == Operation.DEPOSIT:
             required_perms.append('kfet.can_perform_deposit')
 
@@ -452,7 +455,7 @@ def kpsul_perform_operations(request):
     # Filling cof status for statistics
     operationgroup.is_cof = operationgroup.on_acc.is_cof
 
-    # Updating account's balance
+    # Updating (no commit) account's balance
     operationgroup.on_acc.balance += operationgroup.amount
 
     # Apply all saves in a transaction to ensure database integrity
@@ -466,9 +469,12 @@ def kpsul_perform_operations(request):
             operationgroup.on_acc.save()
 
             # Filling operationgroup id for each operations and saving
+            # Saving articles with new stock
             for operation in operations:
                 operation.group = operationgroup
                 operation.save()
+                if operation.type == Operation.PURCHASE:
+                    operation.article.save()
                 data['operations'].append(operation.pk)
     except IntegrityError:
         data['errors'].append('DB error')