diff --git a/passerelle/contrib/toulouse_maelis/models.py b/passerelle/contrib/toulouse_maelis/models.py
index e3dfa280..d29724dc 100644
--- a/passerelle/contrib/toulouse_maelis/models.py
+++ b/passerelle/contrib/toulouse_maelis/models.py
@@ -3931,7 +3931,7 @@ class ToulouseMaelis(BaseResource, HTTPResource):
                         invoice.maelis_data = item
                         invoice.maelis_data_update_date = now()
                         invoice.save()
-                        complete_diff = difflib.ndiff(content_two.split('\n'), content_one.split('\n'))
+                        complete_diff = difflib.ndiff(content_one.split('\n'), content_two.split('\n'))
                         diff = [x for x in complete_diff if x[0] in ['-', '+']]
                         self.logger.info(
                             "Mise à jour de %s sur la famille '%s': %s", repr(invoice), family_id, diff
diff --git a/tests/test_toulouse_maelis.py b/tests/test_toulouse_maelis.py
index bc682268..ffe93626 100644
--- a/tests/test_toulouse_maelis.py
+++ b/tests/test_toulouse_maelis.py
@@ -8970,7 +8970,7 @@ def test_invoices(invoice_service, con, app, caplog, freezer):
     assert invoice.maelis_data_update_date.strftime('%Y-%m-%d %H:%M:%S') == '2023-03-03 18:00:00'
     assert invoice.status() == 'created'
 
-    # Simulate change
+    # Simulate change: PDF file no more available
     invoice.maelis_data['pdfName'] = 'invoice.pdf'
     invoice.save()
 
@@ -8982,7 +8982,7 @@ def test_invoices(invoice_service, con, app, caplog, freezer):
     assert len([x for x in caplog.records if 'Mise à jour de <Invoice "104/' in x.message]) == 1
     assert (
         caplog.records[-1].message
-        == 'Mise à jour de <Invoice "104/30"> sur la famille \'1312\': [\'-   "pdfName": null,\', \'+   "pdfName": "invoice.pdf",\']'
+        == 'Mise à jour de <Invoice "104/30"> sur la famille \'1312\': [\'-   "pdfName": "invoice.pdf",\', \'+   "pdfName": null,\']'
     )
 
     invoice = con.invoice_set.get(regie_id=104, invoice_id=30)