diff --git a/swh/storage/filter.py b/swh/storage/filter.py
--- a/swh/storage/filter.py
+++ b/swh/storage/filter.py
@@ -19,10 +19,9 @@
 
         storage:
           cls: filter
-          args:
-            storage:
-              cls: remote
-              args: http://storage.internal.staging.swh.network:5002/
+          storage:
+            cls: remote
+            url: http://storage.internal.staging.swh.network:5002/
 
     """
     def __init__(self, storage):
diff --git a/swh/storage/tests/conftest.py b/swh/storage/tests/conftest.py
--- a/swh/storage/tests/conftest.py
+++ b/swh/storage/tests/conftest.py
@@ -38,19 +38,17 @@
 def swh_storage(postgresql_proc, swh_storage_postgresql):
     storage_config = {
         'cls': 'local',
-        'args': {
-            'db': 'postgresql://{user}@{host}:{port}/{dbname}'.format(
-                host=postgresql_proc.host,
-                port=postgresql_proc.port,
-                user='postgres',
-                dbname='tests'),
-            'objstorage': {
-                'cls': 'memory',
-                'args': {}
-            },
-            'journal_writer': {
-                'cls': 'memory',
-            },
+        'db': 'postgresql://{user}@{host}:{port}/{dbname}'.format(
+            host=postgresql_proc.host,
+            port=postgresql_proc.port,
+            user='postgres',
+            dbname='tests'),
+        'objstorage': {
+            'cls': 'memory',
+            'args': {}
+        },
+        'journal_writer': {
+            'cls': 'memory',
         },
     }
     storage = swh.storage.get_storage(**storage_config)
diff --git a/swh/storage/tests/test_api_client.py b/swh/storage/tests/test_api_client.py
--- a/swh/storage/tests/test_api_client.py
+++ b/swh/storage/tests/test_api_client.py
@@ -20,10 +20,8 @@
 def app():
     storage_config = {
         'cls': 'memory',
-        'args': {
-            'journal_writer': {
-                'cls': 'memory',
-            },
+        'journal_writer': {
+            'cls': 'memory',
         },
     }
     server.storage = swh.storage.get_storage(**storage_config)
diff --git a/swh/storage/tests/test_buffer.py b/swh/storage/tests/test_buffer.py
--- a/swh/storage/tests/test_buffer.py
+++ b/swh/storage/tests/test_buffer.py
@@ -9,7 +9,7 @@
 def test_buffering_proxy_storage_content_threshold_not_hit(sample_data):
     contents = sample_data['content']
     storage = BufferingProxyStorage(
-        storage={'cls': 'memory', 'args': {}},
+        storage={'cls': 'memory'},
         min_batch_size={
             'content': 10,
         }
@@ -38,7 +38,7 @@
 def test_buffering_proxy_storage_content_threshold_nb_hit(sample_data):
     contents = sample_data['content']
     storage = BufferingProxyStorage(
-        storage={'cls': 'memory', 'args': {}},
+        storage={'cls': 'memory'},
         min_batch_size={
             'content': 1,
         }
@@ -62,7 +62,7 @@
     contents = sample_data['content']
     content_bytes_min_batch_size = 20
     storage = BufferingProxyStorage(
-        storage={'cls': 'memory', 'args': {}},
+        storage={'cls': 'memory'},
         min_batch_size={
             'content': 10,
             'content_bytes': content_bytes_min_batch_size,
@@ -88,7 +88,7 @@
 def test_buffering_proxy_storage_directory_threshold_not_hit(sample_data):
     directories = sample_data['directory']
     storage = BufferingProxyStorage(
-        storage={'cls': 'memory', 'args': {}},
+        storage={'cls': 'memory'},
         min_batch_size={
             'directory': 10,
         }
@@ -114,7 +114,7 @@
 def test_buffering_proxy_storage_directory_threshold_hit(sample_data):
     directories = sample_data['directory']
     storage = BufferingProxyStorage(
-        storage={'cls': 'memory', 'args': {}},
+        storage={'cls': 'memory'},
         min_batch_size={
             'directory': 1,
         }
@@ -135,7 +135,7 @@
 def test_buffering_proxy_storage_revision_threshold_not_hit(sample_data):
     revisions = sample_data['revision']
     storage = BufferingProxyStorage(
-        storage={'cls': 'memory', 'args': {}},
+        storage={'cls': 'memory'},
         min_batch_size={
             'revision': 10,
         }
@@ -161,7 +161,7 @@
 def test_buffering_proxy_storage_revision_threshold_hit(sample_data):
     revisions = sample_data['revision']
     storage = BufferingProxyStorage(
-        storage={'cls': 'memory', 'args': {}},
+        storage={'cls': 'memory'},
         min_batch_size={
             'revision': 1,
         }
diff --git a/swh/storage/tests/test_filter.py b/swh/storage/tests/test_filter.py
--- a/swh/storage/tests/test_filter.py
+++ b/swh/storage/tests/test_filter.py
@@ -9,7 +9,7 @@
 
 def test_filtering_proxy_storage_content(sample_data):
     sample_content = sample_data['content'][0]
-    storage = FilteringProxyStorage(storage={'cls': 'memory', 'args': {}})
+    storage = FilteringProxyStorage(storage={'cls': 'memory'})
 
     content = next(storage.content_get([sample_content['sha1']]))
     assert not content
@@ -34,7 +34,7 @@
 
 def test_filtering_proxy_storage_revision(sample_data):
     sample_revision = sample_data['revision'][0]
-    storage = FilteringProxyStorage(storage={'cls': 'memory', 'args': {}})
+    storage = FilteringProxyStorage(storage={'cls': 'memory'})
 
     revision = next(storage.revision_get([sample_revision['id']]))
     assert not revision
@@ -55,7 +55,7 @@
 
 def test_filtering_proxy_storage_directory(sample_data):
     sample_directory = sample_data['directory'][0]
-    storage = FilteringProxyStorage(storage={'cls': 'memory', 'args': {}})
+    storage = FilteringProxyStorage(storage={'cls': 'memory'})
 
     directory = next(storage.directory_missing([sample_directory['id']]))
     assert directory
diff --git a/swh/storage/tests/test_in_memory.py b/swh/storage/tests/test_in_memory.py
--- a/swh/storage/tests/test_in_memory.py
+++ b/swh/storage/tests/test_in_memory.py
@@ -18,10 +18,8 @@
 def swh_storage():
     storage_config = {
         'cls': 'memory',
-        'args': {
-            'journal_writer': {
-                'cls': 'memory',
-            },
+        'journal_writer': {
+            'cls': 'memory',
         },
     }
     storage = get_storage(**storage_config)