diff --git a/stock_request/models/stock_request.py b/stock_request/models/stock_request.py
index f807724f..656ec130 100644
--- a/stock_request/models/stock_request.py
+++ b/stock_request/models/stock_request.py
@@ -125,6 +125,18 @@ def _get_expected_date():
         ("name_uniq", "unique(name, company_id)", "Stock Request name must be unique")
     ]
 
+    @api.constrains("state", "product_qty")
+    def _check_qty(self):
+        for rec in self:
+            if rec.state == "draft" and rec.product_qty <= 0:
+                raise ValidationError(
+                    _("Stock Request product quantity has to be strictly positive.")
+                )
+            elif rec.state != "draft" and rec.product_qty < 0:
+                raise ValidationError(
+                    _("Stock Request product quantity cannot be negative.")
+                )
+
     def _get_all_origin_moves(self, move):
         all_moves = move
         if move.move_orig_ids:
diff --git a/stock_request/models/stock_request_abstract.py b/stock_request/models/stock_request_abstract.py
index 5ab1f142..76adf338 100644
--- a/stock_request/models/stock_request_abstract.py
+++ b/stock_request/models/stock_request_abstract.py
@@ -206,14 +206,6 @@ def _check_product_uom(self):
                 )
             )
 
-    @api.constrains("product_qty")
-    def _check_qty(self):
-        for rec in self:
-            if rec.product_qty <= 0:
-                raise ValidationError(
-                    _("Stock Request product quantity has to be strictly positive.")
-                )
-
     @api.onchange("warehouse_id")
     def onchange_warehouse_id(self):
         """Finds location id for changed warehouse."""
diff --git a/stock_request_purchase/models/stock_request.py b/stock_request_purchase/models/stock_request.py
index 931ba36e..b2d1c36b 100644
--- a/stock_request_purchase/models/stock_request.py
+++ b/stock_request_purchase/models/stock_request.py
@@ -42,10 +42,11 @@ def _check_purchase_company_constrains(self):
     def action_cancel(self):
         """Propagate the cancellation to the generated purchase orders."""
         res = super().action_cancel()
-        self.sudo().purchase_ids.filtered(
-            lambda x: x.state not in ("purchase", "done", "cancel")
-            and x.stock_request_ids == self
-        ).button_cancel()
+        if not self.env.context.get("skip_cancel_po_from_stock_request"):
+            self.sudo().purchase_ids.filtered(
+                lambda x: x.state not in ("purchase", "done", "cancel")
+                and x.stock_request_ids == self
+            ).button_cancel()
         return res
 
     def action_view_purchase(self):