diff --git a/anonstream/control/spec/common.py b/anonstream/control/spec/common.py
index bfee339..df4312b 100644
--- a/anonstream/control/spec/common.py
+++ b/anonstream/control/spec/common.py
@@ -3,9 +3,14 @@
 
 import json
 
-from anonstream.control.spec import Spec, NoParse, Ambiguous, Parsed
+from quart import current_app
+
+from anonstream.control.spec import Spec, NoParse, Ambiguous, BadArgument, Parsed
 from anonstream.control.spec.utils import get_item, startswith
 
+USERS_BY_TOKEN = current_app.users_by_token
+USERS = current_app.users
+
 class Str(Spec):
     AS_ARG = False
 
@@ -146,3 +151,26 @@ class ArgsJsonStringArray(ArgsJson):
                 f'bad argument at position {index} {obj_json!r}: '
                 f'could not decode json array of strings'
             )
+
+class ArgsJsonTokenUser(ArgsJsonString):
+    def transform_obj(self, token):
+        try:
+            user = USERS_BY_TOKEN[token]
+        except KeyError:
+            raise BadArgument(f'no user with token {token!r}')
+        return user
+
+class ArgsJsonHashUser(ArgsString):
+    def transform_string(self, token_hash):
+        for user in USERS:
+            if user['token_hash'] == token_hash:
+                break
+        else:
+            raise BadArgument(f'no user with token_hash {token_hash!r}')
+        return user
+
+def ArgsUser(spec):
+    return Str({
+        'token': ArgsJsonTokenUser(spec),
+        'hash': ArgsJsonHashUser(spec),
+    })
diff --git a/anonstream/control/spec/methods/user.py b/anonstream/control/spec/methods/user.py
index 88af4bb..5cd91fd 100644
--- a/anonstream/control/spec/methods/user.py
+++ b/anonstream/control/spec/methods/user.py
@@ -6,40 +6,15 @@ import json
 from quart import current_app
 
 from anonstream.control.exceptions import CommandFailed
-from anonstream.control.spec import BadArgument
-from anonstream.control.spec.common import Str, End, ArgsInt, ArgsString, ArgsJson, ArgsJsonBoolean, ArgsJsonString
-from anonstream.control.spec.utils import get_item, json_dumps_contiguous
+from anonstream.control.spec.common import Str, End, ArgsInt, ArgsString, ArgsJson, ArgsJsonBoolean, ArgsJsonString, ArgsUser
+from anonstream.control.spec.utils import json_dumps_contiguous
 from anonstream.utils.user import USER_WEBSOCKET_ATTRS
 from anonstream.routes.wrappers import generate_and_add_user
 from anonstream.wrappers import get_timestamp
 
 USERS_BY_TOKEN = current_app.users_by_token
-USERS = current_app.users
 USERS_UPDATE_BUFFER = current_app.users_update_buffer
 
-class ArgsJsonTokenUser(ArgsJsonString):
-    def transform_obj(self, token):
-        try:
-            user = USERS_BY_TOKEN[token]
-        except KeyError:
-            raise BadArgument(f'no user with token {token!r}')
-        return user
-
-class ArgsJsonHashUser(ArgsString):
-    def transform_string(self, token_hash):
-        for user in USERS:
-            if user['token_hash'] == token_hash:
-                break
-        else:
-            raise BadArgument(f'no user with token_hash {token_hash!r}')
-        return user
-
-def ArgsUser(spec):
-    return Str({
-        'token': ArgsJsonTokenUser(spec),
-        'hash': ArgsJsonHashUser(spec),
-    })
-
 async def cmd_user_help():
     normal = ['user', 'help']
     response = (