diff --git a/passerelle/apps/opengis/models.py b/passerelle/apps/opengis/models.py
index 9beb0e3e..f5ceb8f3 100644
--- a/passerelle/apps/opengis/models.py
+++ b/passerelle/apps/opengis/models.py
@@ -73,18 +73,21 @@ class OpenGIS(BaseResource):
     class Meta:
         verbose_name = _('OpenGIS')
 
-    def get_service_version(self, service_type, service_url, renew=False):
+    def get_capabilities(self, service_type, service_url):
         if not service_url:
             raise APIError('no %s URL declared' % service_type)
+        return self.requests.get(
+            service_url,
+            params={'request': 'GetCapabilities', 'service': service_type.upper()},
+        )
+
+    def get_service_version(self, service_type, service_url, renew=False):
         cache_key = 'opengis-%s-%s-version' % (service_type, self.id)
         if not renew:
             service_version = cache.get(cache_key)
             if service_version:
                 return service_version
-        response = self.requests.get(
-                service_url,
-                params={'request': 'GetCapabilities', 'service': service_type.upper()},
-                )
+        response = self.get_capabilities(service_type, service_url)
         element = ET.fromstring(response.content)
         service_version = element.attrib.get('version')
         # cache version number for an hour
@@ -97,6 +100,23 @@ class OpenGIS(BaseResource):
     def get_wfs_service_version(self, renew=False):
         return self.get_service_version('wfs', self.wfs_service_url, renew=renew)
 
+    def get_output_format(self):
+        cache_key = 'opengis-%s-output-format' % self.id
+        output_format = cache.get(cache_key)
+        if output_format:
+            return output_format
+        response = self.get_capabilities('wfs', self.wfs_service_url)
+        element = ET.fromstring(response.content)
+        ns = {'ows': 'http://www.opengis.net/ows/1.1'}
+        formats = element.findall('.//ows:Operation[@name="GetFeature"]/'
+                                  'ows:Parameter[@name="outputFormat"]/'
+                                  'ows:AllowedValues/ows:Value', ns)
+        for output_format in formats:
+            if 'json' in output_format.text.lower():
+                cache.set(cache_key, output_format.text, 3600)
+                return output_format.text
+        raise APIError('WFS server doesn\'t support json output format for GetFeature request')
+
     def get_typename_label(self):
         version_str = self.get_wfs_service_version()
         version_tuple = tuple(int(x) for x in version_str.split('.'))
@@ -123,6 +143,19 @@ class OpenGIS(BaseResource):
                 })
             response.raise_for_status()
 
+    def build_get_features_params(self, typename=None, property_name=None, cql_filter=None):
+        params = {
+            'version': self.get_wfs_service_version(),
+            'service': 'WFS',
+            'request': 'GetFeature',
+            self.get_typename_label(): typename,
+            'propertyName': property_name,
+            'outputFormat': self.get_output_format(),
+        }
+        if cql_filter:
+            params['cql_filter'] = cql_filter
+        return params
+
     @endpoint(perm='can_access', description='Get features',
               parameters={
                   'type_names': {
@@ -152,22 +185,14 @@ class OpenGIS(BaseResource):
               })
     def features(self, request, type_names, property_name, cql_filter=None,
                  filter_property_name=None, q=None, **kwargs):
-        params = {
-            'VERSION': self.get_wfs_service_version(),
-            'SERVICE': 'WFS',
-            'REQUEST': 'GetFeature',
-            self.get_typename_label(): type_names,
-            'PROPERTYNAME': property_name,
-            'OUTPUTFORMAT': 'json',
-        }
         if cql_filter:
-            params.update({'CQL_FILTER': cql_filter})
             if filter_property_name and q:
                 if 'case-insensitive' in kwargs:
                     operator = 'ILIKE'
                 else:
                     operator = 'LIKE'
-                params['CQL_FILTER'] += ' AND %s %s \'%%%s%%\'' % (filter_property_name, operator, q)
+                cql_filter += ' AND %s %s \'%%%s%%\'' % (filter_property_name, operator, q)
+        params = self.build_get_features_params(type_names, property_name, cql_filter)
         response = self.requests.get(self.wfs_service_url, params=params)
         data = []
         try:
@@ -297,14 +322,7 @@ class OpenGIS(BaseResource):
         lon, lat = self.convert_coordinates(lon, lat)
 
         cql_filter = 'DWITHIN(the_geom,Point(%.6f %.6f),%s,meters)' % (lon, lat, self.search_radius)
-        params = {
-            'VERSION': self.get_wfs_service_version(),
-            'SERVICE': 'WFS',
-            'REQUEST': 'GetFeature',
-            self.get_typename_label(): self.query_layer,
-            'OUTPUTFORMAT': 'json',
-            'CQL_FILTER': cql_filter
-        }
+        params = self.build_get_features_params(typename=self.query_layer, cql_filter=cql_filter)
         response = self.requests.get(self.wfs_service_url, params=params)
         if not response.ok:
             raise APIError('Webservice returned status code %s' % response.status_code)
diff --git a/tests/test_opengis.py b/tests/test_opengis.py
index 07d3fdfb..fa5e2de7 100644
--- a/tests/test_opengis.py
+++ b/tests/test_opengis.py
@@ -39,6 +39,16 @@ FAKE_SERVICE_CAPABILITIES = '''<?xml version="1.0" encoding="UTF-8"?>
         <ows:ServiceType>WFS</ows:ServiceType><ows:ServiceTypeVersion>2.0.0</ows:ServiceTypeVersion><ows:Fees/>
         <ows:AccessConstraints/>
     </ows:ServiceIdentification>
+    <ows:OperationsMetadata>
+        <ows:Operation name="GetFeature">
+            <ows:Parameter name="outputFormat">
+                <ows:AllowedValues>
+                    <ows:Value>application/gml+xml; version=3.2</ows:Value>
+                    <ows:Value>application/json; subtype=geojson</ows:Value>
+                </ows:AllowedValues>
+            </ows:Parameter>
+        </ows:Operation>
+    </ows:OperationsMetadata>
 </wfs:WFS_Capabilities>'''
 
 FAKE_SERVICE_CAPABILITIES_V1_0_0 = '''<?xml version="1.0" encoding="UTF-8"?>
@@ -50,6 +60,16 @@ FAKE_SERVICE_CAPABILITIES_V1_0_0 = '''<?xml version="1.0" encoding="UTF-8"?>
         <ows:ServiceType>WFS</ows:ServiceType><ows:ServiceTypeVersion>1.0.0</ows:ServiceTypeVersion><ows:Fees/>
         <ows:AccessConstraints/>
     </ows:ServiceIdentification>
+    <ows:OperationsMetadata>
+        <ows:Operation name="GetFeature">
+            <ows:Parameter name="outputFormat">
+                <ows:AllowedValues>
+                    <ows:Value>application/gml+xml; version=3.2</ows:Value>
+                    <ows:Value>application/json; subtype=geojson</ows:Value>
+                </ows:AllowedValues>
+            </ows:Parameter>
+        </ows:Operation>
+    </ows:OperationsMetadata>
 </wfs:WFS_Capabilities>'''
 
 FAKE_FEATURES_JSON = '''
@@ -326,12 +346,12 @@ def test_get_feature(mocked_get, app, connector):
     assert endpoint == '/opengis/test/features'
     mocked_get.side_effect = geoserver_responses
     resp = app.get(endpoint, params={'type_names': 'ref_metro_limites_communales', 'property_name': 'nom'})
-    assert mocked_get.call_args[1]['params']['REQUEST'] == 'GetFeature'
-    assert mocked_get.call_args[1]['params']['PROPERTYNAME'] == 'nom'
+    assert mocked_get.call_args[1]['params']['request'] == 'GetFeature'
+    assert mocked_get.call_args[1]['params']['propertyName'] == 'nom'
     assert mocked_get.call_args[1]['params']['TYPENAMES'] == 'ref_metro_limites_communales'
-    assert mocked_get.call_args[1]['params']['OUTPUTFORMAT'] == 'json'
-    assert mocked_get.call_args[1]['params']['SERVICE'] == 'WFS'
-    assert mocked_get.call_args[1]['params']['VERSION'] == connector.get_wfs_service_version()
+    assert 'json' in mocked_get.call_args[1]['params']['outputFormat']
+    assert mocked_get.call_args[1]['params']['service'] == 'WFS'
+    assert mocked_get.call_args[1]['params']['version'] == connector.get_wfs_service_version()
     assert len(resp.json['data']) == 7
     for item in resp.json['data']:
         assert 'text' in item
@@ -347,7 +367,7 @@ def test_get_filtered_feature(mocked_get, app, connector):
                 'property_name': 'nom',
                 'cql_filter': 'nom=\'Fontaine\''
             })
-    assert mocked_get.call_args[1]['params']['CQL_FILTER'] == 'nom=\'Fontaine\''
+    assert mocked_get.call_args[1]['params']['cql_filter'] == 'nom=\'Fontaine\''
 
 
 @mock.patch('passerelle.utils.Request.get')
@@ -358,16 +378,16 @@ def test_get_filtered_by_property_feature(mocked_get, app, connector):
               'property_name': 'nom', 'cql_filter': 'nom=\'Fontaine\'',
               'filter_property_name': 'nom'}
     app.get(endpoint, params=params)
-    assert mocked_get.call_args[1]['params']['CQL_FILTER'] == 'nom=\'Fontaine\''
+    assert mocked_get.call_args[1]['params']['cql_filter'] == 'nom=\'Fontaine\''
     params['q'] = 'bens'
     app.get(endpoint, params=params)
-    assert mocked_get.call_args[1]['params']['CQL_FILTER'] == 'nom=\'Fontaine\' AND nom LIKE \'%bens%\''
+    assert mocked_get.call_args[1]['params']['cql_filter'] == 'nom=\'Fontaine\' AND nom LIKE \'%bens%\''
     params['case-insensitive'] = True
     app.get(endpoint, params=params)
-    assert mocked_get.call_args[1]['params']['CQL_FILTER'] == 'nom=\'Fontaine\' AND nom ILIKE \'%bens%\''
+    assert mocked_get.call_args[1]['params']['cql_filter'] == 'nom=\'Fontaine\' AND nom ILIKE \'%bens%\''
     params.pop('cql_filter')
     app.get(endpoint, params=params)
-    assert 'CQL_FILTER' not in mocked_get.call_args[1]['params']
+    assert 'cql_filter' not in mocked_get.call_args[1]['params']
 
 
 @mock.patch('passerelle.utils.Request.get')
@@ -379,12 +399,12 @@ def test_get_feature_error(mocked_get, app, connector):
         'type_names': 'ref_metro_limites_communales',
         'property_name': 'nom'
     })
-    assert mocked_get.call_args[1]['params']['REQUEST'] == 'GetFeature'
-    assert mocked_get.call_args[1]['params']['PROPERTYNAME'] == 'nom'
+    assert mocked_get.call_args[1]['params']['request'] == 'GetFeature'
+    assert mocked_get.call_args[1]['params']['propertyName'] == 'nom'
     assert mocked_get.call_args[1]['params']['TYPENAMES'] == 'ref_metro_limites_communales'
-    assert mocked_get.call_args[1]['params']['OUTPUTFORMAT'] == 'json'
-    assert mocked_get.call_args[1]['params']['SERVICE'] == 'WFS'
-    assert mocked_get.call_args[1]['params']['VERSION'] == connector.get_wfs_service_version()
+    assert 'json' in mocked_get.call_args[1]['params']['outputFormat']
+    assert mocked_get.call_args[1]['params']['service'] == 'WFS'
+    assert mocked_get.call_args[1]['params']['version'] == connector.get_wfs_service_version()
     result = resp.json
     assert result['err'] == 1
     assert result['err_desc'] == 'OpenGIS Error: NoApplicableCode'
@@ -400,12 +420,12 @@ def test_get_feature_error2(mocked_get, app, connector):
         'type_names': 'ref_metro_limites_communales',
         'property_name': 'nom'
     })
-    assert mocked_get.call_args[1]['params']['REQUEST'] == 'GetFeature'
-    assert mocked_get.call_args[1]['params']['PROPERTYNAME'] == 'nom'
+    assert mocked_get.call_args[1]['params']['request'] == 'GetFeature'
+    assert mocked_get.call_args[1]['params']['propertyName'] == 'nom'
     assert mocked_get.call_args[1]['params']['TYPENAMES'] == 'ref_metro_limites_communales'
-    assert mocked_get.call_args[1]['params']['OUTPUTFORMAT'] == 'json'
-    assert mocked_get.call_args[1]['params']['SERVICE'] == 'WFS'
-    assert mocked_get.call_args[1]['params']['VERSION'] == connector.get_wfs_service_version()
+    assert 'json' in mocked_get.call_args[1]['params']['outputFormat']
+    assert mocked_get.call_args[1]['params']['service'] == 'WFS'
+    assert mocked_get.call_args[1]['params']['version'] == connector.get_wfs_service_version()
     result = resp.json
     assert result['err'] == 1
     assert result['err_desc'] == 'OpenGIS Error: unparsable error'
@@ -421,8 +441,8 @@ def test_typename_parameter_upgrade(mocked_get, server_responses, version, typen
     assert endpoint == '/opengis/test/features'
     mocked_get.side_effect = server_responses
     resp = app.get(endpoint, params={'type_names': '...', 'property_name': '...'})
-    assert mocked_get.call_args[1]['params']['REQUEST'] == 'GetFeature'
-    assert mocked_get.call_args[1]['params']['VERSION'] == version
+    assert mocked_get.call_args[1]['params']['request'] == 'GetFeature'
+    assert mocked_get.call_args[1]['params']['version'] == version
     assert typename_label in mocked_get.call_args[1]['params'].keys()
 
 
@@ -445,7 +465,7 @@ def test_reverse_geocoding(mocked_get, app, connector):
                        'lat': '45.1893469606986',
                        'lon': '5.72462060798'
                    })
-    assert (mocked_get.call_args[1]['params']['CQL_FILTER']
+    assert (mocked_get.call_args[1]['params']['cql_filter']
             == 'DWITHIN(the_geom,Point(1914061.486036 4224640.457791),45,meters)')
     assert resp.json['lon'] == '5.724077'
     assert resp.json['lat'] == '45.189397'
@@ -464,7 +484,7 @@ def test_reverse_geocoding(mocked_get, app, connector):
             'lat': '45.183784',
             'lon': '5.714885'
         })
-    assert mocked_get.call_args[1]['params']['CQL_FILTER'] == 'DWITHIN(the_geom,Point(5.714885 45.183784),10,meters)'
+    assert mocked_get.call_args[1]['params']['cql_filter'] == 'DWITHIN(the_geom,Point(5.714885 45.183784),10,meters)'
     assert resp.json['err'] == 1
     assert resp.json['err_desc'] == 'Unable to geocode'