diff --git a/freqtrade/rpc/api_server.py b/freqtrade/rpc/api_server.py
index 711202b27..67bbfdc78 100644
--- a/freqtrade/rpc/api_server.py
+++ b/freqtrade/rpc/api_server.py
@@ -2,7 +2,7 @@ import logging
 import threading
 from datetime import date, datetime
 from ipaddress import IPv4Address
-from typing import Dict
+from typing import Dict, Callable, Any
 
 from arrow import Arrow
 from flask import Flask, jsonify, request
@@ -34,41 +34,45 @@ class ArrowJSONEncoder(JSONEncoder):
         return JSONEncoder.default(self, obj)
 
 
+# Type should really be Callable[[ApiServer, Any], Any], but that will create a circular dependency
+def require_login(func: Callable[[Any, Any], Any]):
+
+    def func_wrapper(obj, *args, **kwargs):
+
+        auth = request.authorization
+        if auth and obj.check_auth(auth.username, auth.password):
+            return func(obj, *args, **kwargs)
+        else:
+            return jsonify({"error": "Unauthorized"}), 401
+
+    return func_wrapper
+
+
+# Type should really be Callable[[ApiServer], Any], but that will create a circular dependency
+def rpc_catch_errors(func: Callable[[Any], Any]):
+
+    def func_wrapper(obj, *args, **kwargs):
+
+        try:
+            return func(obj, *args, **kwargs)
+        except RPCException as e:
+            logger.exception("API Error calling %s: %s", func.__name__, e)
+            return obj.rest_error(f"Error querying {func.__name__}: {e}")
+
+    return func_wrapper
+
+
 class ApiServer(RPC):
     """
     This class runs api server and provides rpc.rpc functionality to it
 
-    This class starts a none blocking thread the api server runs within
+    This class starts a non-blocking thread the api server runs within
     """
 
-    def rpc_catch_errors(func):
-
-        def func_wrapper(self, *args, **kwargs):
-
-            try:
-                return func(self, *args, **kwargs)
-            except RPCException as e:
-                logger.exception("API Error calling %s: %s", func.__name__, e)
-                return self.rest_error(f"Error querying {func.__name__}: {e}")
-
-        return func_wrapper
-
     def check_auth(self, username, password):
         return (username == self._config['api_server'].get('username') and
                 password == self._config['api_server'].get('password'))
 
-    def require_login(func):
-
-        def func_wrapper(self, *args, **kwargs):
-
-            auth = request.authorization
-            if auth and self.check_auth(auth.username, auth.password):
-                return func(self, *args, **kwargs)
-            else:
-                return jsonify({"error": "Unauthorized"}), 401
-
-        return func_wrapper
-
     def __init__(self, freqtrade) -> None:
         """
         Init the api server, and init the super class RPC
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 0578c03bd..f5cde59e8 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -7,7 +7,7 @@ coveralls==1.8.2
 flake8==3.7.8
 flake8-type-annotations==0.1.0
 flake8-tidy-imports==3.0.0
-mypy==0.730
+mypy==0.740
 pytest==5.2.1
 pytest-asyncio==0.10.0
 pytest-cov==2.8.1