diff --git a/passerelle/views.py b/passerelle/views.py
index 4e596041..978ce48d 100644
--- a/passerelle/views.py
+++ b/passerelle/views.py
@@ -388,12 +388,19 @@ class GenericEndpointView(GenericConnectorMixin, SingleObjectMixin, View):
                 except ValueError:
                     raise InvalidParameterValue(parameter)
             elif parameter_info.get('type') == 'date':
-                try:
-                    d[parameter] = parse_date(d[parameter].strip())
-                except ValueError:
-                    raise InvalidParameterValue('%s (not a valid date)' % parameter)
-                if not d[parameter]:
-                    raise InvalidParameterValue('%s (YYYY-MM-DD expected)' % parameter)
+                if (
+                    parameter_info.get('optional')
+                    and parameter_info.get('default_value') is None
+                    and not d[parameter]
+                ):
+                    d[parameter] = None
+                else:
+                    try:
+                        d[parameter] = parse_date(d[parameter].strip())
+                    except ValueError:
+                        raise InvalidParameterValue('%s (not a valid date)' % parameter)
+                    if not d[parameter]:
+                        raise InvalidParameterValue('%s (YYYY-MM-DD expected)' % parameter)
         if request.method == 'POST' and self.endpoint.endpoint_info.post:
             request_body = self.endpoint.endpoint_info.post.get('request_body', {})
             if 'application/json' in request_body.get('schema', {}):
diff --git a/tests/test_generic_endpoint.py b/tests/test_generic_endpoint.py
index ff15bf89..30e94d6f 100644
--- a/tests/test_generic_endpoint.py
+++ b/tests/test_generic_endpoint.py
@@ -748,6 +748,8 @@ def test_endpoint_typed_params(app, db, monkeypatch):
     connector.save()
 
     json_res = app.get('/stub-invoices/fake/httpcall').json
+    assert json_res == {'boolean': False, 'integer': 1, 'floating': 1.1, 'date': None, 'err': 0}
+
     json_res = app.get('/stub-invoices/fake/httpcall?boolean=True').json
     assert json_res['boolean'] is True
     json_res = app.get('/stub-invoices/fake/httpcall?boolean=on').json
@@ -788,12 +790,12 @@ def test_endpoint_typed_params(app, db, monkeypatch):
     json_res = app.get('/stub-invoices/fake/httpcall?date=nodate', status=400).json
     assert json_res['err'] == 1
     assert json_res['err_desc'] == 'invalid value for parameter "date (YYYY-MM-DD expected)"'
-    json_res = app.get('/stub-invoices/fake/httpcall?date=', status=400).json
-    assert json_res['err'] == 1
-    assert json_res['err_desc'] == 'invalid value for parameter "date (YYYY-MM-DD expected)"'
     json_res = app.get('/stub-invoices/fake/httpcall?date=1970-02-31', status=400).json
     assert json_res['err'] == 1
     assert json_res['err_desc'] == 'invalid value for parameter "date (not a valid date)"'
+    json_res = app.get('/stub-invoices/fake/httpcall?date=').json
+    assert not json_res['err']
+    assert json_res['date'] is None
 
 
 def test_endpoint_params_type_detection(app, db, monkeypatch):