diff --git a/operation.py b/operation.py
index 77e2e4f..985b4cf 100644
--- a/operation.py
+++ b/operation.py
@@ -413,7 +413,7 @@ class OperationSubcontrat(metaclass=PoolMeta):
         super().__setup__()
         cls._buttons.update({
                 'create_purchase_request': {
-                    'invisible': ((Eval('state') != 'planned') |
+                    'invisible': (~(Eval('state').in_(['planned', 'waiting'])) |
                         ~Bool(Eval('subcontracted_product',-1))),
                     'readonly': (Bool(Eval('purchase_request',-1)))
                 },