diff --git a/addons/account/report/account_invoice_report.py b/addons/account/report/account_invoice_report.py
index 05be7856475..71adc047fec 100644
--- a/addons/account/report/account_invoice_report.py
+++ b/addons/account/report/account_invoice_report.py
@@ -100,7 +100,7 @@ class AccountInvoiceReport(models.Model):
                 -line.balance * currency_table.rate                         AS price_subtotal,
                 -COALESCE(
                    -- Average line price
-                   (line.balance / NULLIF(line.quantity, 0.0))
+                   (line.balance / NULLIF(line.quantity, 0.0)) * (CASE WHEN move.move_type IN ('in_invoice','out_refund','in_receipt') THEN -1 ELSE 1 END)
                    -- convert to template uom
                    * (NULLIF(COALESCE(uom_line.factor, 1), 0.0) / NULLIF(COALESCE(uom_template.factor, 1), 0.0)),
                    0.0) * currency_table.rate                               AS price_average,
diff --git a/addons/account/tests/test_account_invoice_report.py b/addons/account/tests/test_account_invoice_report.py
index 1a4526cd038..d1458036c9d 100644
--- a/addons/account/tests/test_account_invoice_report.py
+++ b/addons/account/tests/test_account_invoice_report.py
@@ -103,6 +103,7 @@ class TestAccountInvoiceReport(AccountTestInvoicingCommon):
             'price_subtotal': vals[1],
             'quantity': vals[2],
         } for vals in expected_values_list]
+
         self.assertRecordValues(reports, expected_values_dict)
 
     def test_invoice_report_multiple_types(self):
@@ -112,7 +113,7 @@ class TestAccountInvoiceReport(AccountTestInvoicingCommon):
             [1000, 1000, 1],
             [250, 750, 3],
             [6, 6, 1],
-            [-20, -20, -1],
-            [-20, -20, -1],
-            [-600, -600, -1],
+            [20, -20, -1],
+            [20, -20, -1],
+            [600, -600, -1],
         ])