diff --git a/purchase.py b/purchase.py
index 780f05a8e8..f8f5e53d19 100644
--- a/purchase.py
+++ b/purchase.py
@@ -4,6 +4,7 @@ from trytond.model import fields
 from trytond.pool import PoolMeta, Pool
 from trytond.pyson import Eval, If
 
+from trytond.modules.currency.fields import Monetary
 from trytond.modules.product import price_digits, round_price
 
 
@@ -37,9 +38,8 @@ class Line(metaclass=PoolMeta):
             },
         depends=['product_secondary_uom_category', 'type',
             'secondary_uom_factor', 'secondary_uom_rate', 'purchase_state'])
-    secondary_unit_price = fields.Function(
-        fields.Numeric(
-            "Secondary Unit Price", digits=price_digits,
+    secondary_unit_price = fields.Function(Monetary(
+            "Secondary Unit Price", currency='currency', digits=price_digits,
             states={
                 'invisible': ((Eval('type') != 'line')
                     | ~Eval('secondary_unit')),
diff --git a/view/purchase_line_form.xml b/view/purchase_line_form.xml
index 7d739b0b1d..d27b50cf2c 100644
--- a/view/purchase_line_form.xml
+++ b/view/purchase_line_form.xml
@@ -9,7 +9,7 @@ this repository contains the full copyright notices and license terms. -->
         <label name="secondary_unit" string="Unit:"/>
         <field name="secondary_unit"/>
         <label name="secondary_unit_price" string="Unit Price:"/>
-        <field name="secondary_unit_price" symbol="currency"/>
+        <field name="secondary_unit_price"/>
         <newline/>
     </xpath>
 </data>
diff --git a/view/purchase_line_tree.xml b/view/purchase_line_tree.xml
index 3fb140383f..b29c985350 100644
--- a/view/purchase_line_tree.xml
+++ b/view/purchase_line_tree.xml
@@ -4,6 +4,6 @@ this repository contains the full copyright notices and license terms. -->
 <data>
     <xpath expr="//field[@name='unit_price']" position="after">
         <field name="secondary_quantity" symbol="secondary_unit"/>
-        <field name="secondary_unit_price" symbol="currency"/>
+        <field name="secondary_unit_price"/>
     </xpath>
 </data>