diff --git a/addons/mrp/models/mrp_production.py b/addons/mrp/models/mrp_production.py
index 37a7436333b..9713ed31031 100644
--- a/addons/mrp/models/mrp_production.py
+++ b/addons/mrp/models/mrp_production.py
@@ -1836,19 +1836,19 @@ class MrpProduction(models.Model):
             product_uom = initial_move.product_id.uom_id
             if not initial_move.picked:
                 for move_line in initial_move.move_line_ids:
-                    available_qty = move_line.product_uom_id._compute_quantity(move_line.quantity, product_uom)
-                    if float_compare(available_qty, 0, precision_rounding=move_line.product_uom_id.rounding) <= 0:
+                    available_qty = move_line.product_uom_id._compute_quantity(move_line.quantity, product_uom, rounding_method="HALF-UP")
+                    if float_compare(available_qty, 0, precision_rounding=product_uom.rounding) <= 0:
                         continue
                     ml_by_move.append((available_qty, move_line, move_line.copy_data()[0]))
 
             moves = list(initial_move | backorder_moves)
 
             move = moves and moves.pop(0)
-            move_qty_to_reserve = move.product_qty
+            move_qty_to_reserve = move.product_qty  # Product UoM
 
             for index, (quantity, move_line, ml_vals) in enumerate(ml_by_move):
                 taken_qty = min(quantity, move_qty_to_reserve)
-                taken_qty_uom = product_uom._compute_quantity(taken_qty, move_line.product_uom_id)
+                taken_qty_uom = product_uom._compute_quantity(taken_qty, move_line.product_uom_id, rounding_method="HALF-UP")
                 if float_is_zero(taken_qty_uom, precision_rounding=move_line.product_uom_id.rounding):
                     continue
                 move_line.write({
@@ -1867,7 +1867,7 @@ class MrpProduction(models.Model):
                 while float_compare(quantity, 0, precision_rounding=product_uom.rounding) > 0 and move:
                     # Do not create `stock.move.line` if there is no initial demand on `stock.move`
                     taken_qty = min(move_qty_to_reserve, quantity)
-                    taken_qty_uom = product_uom._compute_quantity(taken_qty, move_line.product_uom_id)
+                    taken_qty_uom = product_uom._compute_quantity(taken_qty, move_line.product_uom_id, rounding_method="HALF-UP")
                     if move == initial_move:
                         move_line.quantity += taken_qty_uom
                     elif not float_is_zero(taken_qty_uom, precision_rounding=move_line.product_uom_id.rounding):
diff --git a/addons/mrp/tests/test_backorder.py b/addons/mrp/tests/test_backorder.py
index 35c2f261830..1a883ca92c1 100644
--- a/addons/mrp/tests/test_backorder.py
+++ b/addons/mrp/tests/test_backorder.py
@@ -322,6 +322,35 @@ class TestMrpProductionBackorder(TestMrpCommon):
         # 300 Grams consumed and 700 reserved
         self.assertAlmostEqual(self.env['stock.quant']._gather(product_component, self.stock_location).reserved_quantity, 0.7)
 
+    def test_rounding_backorder(self):
+        """test backorder component rounding doesn't introduce reservation issues"""
+        production, _, _, p1, p2 = self.generate_mo(qty_final=5, qty_base_1=1, qty_base_2=1)
+
+        self.env['stock.quant']._update_available_quantity(p1, self.stock_location, 100)
+        self.env['stock.quant']._update_available_quantity(p2, self.stock_location, 100)
+
+        production.action_assign()
+
+        production_form = Form(production)
+        production_form.qty_producing = 3.1
+        production = production_form.save()
+
+        details_operation_form = Form(production.move_raw_ids.filtered(lambda m: m.product_id == p1), view=self.env.ref('stock.view_stock_move_operations'))
+        with details_operation_form.move_line_ids.edit(0) as ml:
+            ml.quantity = 3.09
+
+        details_operation_form.save()
+
+        action = production.button_mark_done()
+        backorder_form = Form(self.env['mrp.production.backorder'].with_context(**action['context']))
+        backorder_form.save().action_backorder()
+        backorder = production.procurement_group_id.mrp_production_ids[-1]
+        # 3.09 consumed and 1.9 reserved
+        self.assertAlmostEqual(self.env['stock.quant']._gather(p1, self.stock_location).reserved_quantity, 1.9)
+        self.assertAlmostEqual(backorder.move_raw_ids.filtered(lambda m: m.product_id == p1).move_line_ids.quantity, 1.9)
+
+        # Make sure we don't have an unreserve errors
+        backorder.do_unreserve()
 
     def test_tracking_backorder_series_serial_1(self):
         """ Create a MO of 4 tracked products (serial) with pbm_sam.