diff --git a/purchase.py b/purchase.py
index 8b991f5fb5..1a731f4c0e 100644
--- a/purchase.py
+++ b/purchase.py
@@ -220,11 +220,13 @@ class Purchase(Workflow, ModelSQL, ModelView, TaxableMixin):
         cls._buttons.update({
                 'cancel': {
                     'invisible': ~Eval('state').in_(['draft', 'quotation']),
+                    'depends': ['state'],
                     },
                 'draft': {
                     'invisible': ~Eval('state').in_(['cancel', 'quotation']),
                     'icon': If(Eval('state') == 'cancel', 'tryton-clear',
                         'tryton-go-previous'),
+                    'depends': ['state'],
                     },
                 'quote': {
                     'pre_validate': [
@@ -237,24 +239,30 @@ class Purchase(Workflow, ModelSQL, ModelView, TaxableMixin):
                         ],
                     'invisible': Eval('state') != 'draft',
                     'readonly': ~Eval('lines', []),
+                    'depends': ['state'],
                     },
                 'confirm': {
                     'invisible': Eval('state') != 'quotation',
+                    'depends': ['state'],
                     },
                 'process': {
                     'invisible': Eval('state') != 'confirmed',
+                    'depends': ['state'],
                     },
                 'handle_invoice_exception': {
                     'invisible': ((Eval('invoice_state') != 'exception')
                         | (Eval('state') == 'cancel')),
+                    'depends': ['state', 'invoice_state'],
                     },
                 'handle_shipment_exception': {
                     'invisible': ((Eval('shipment_state') != 'exception')
                         | (Eval('state') == 'cancel')),
+                    'depends': ['state', 'shipment_state'],
                     },
                 'modify_header': {
                     'invisible': ((Eval('state') != 'draft')
                         | ~Eval('lines', [-1])),
+                    'depends': ['state'],
                     },
                 })
         # The states where amounts are cached