diff --git a/freqtrade/freqtradebot.py b/freqtrade/freqtradebot.py
index 2bdd8da4b..9562519aa 100644
--- a/freqtrade/freqtradebot.py
+++ b/freqtrade/freqtradebot.py
@@ -58,8 +58,8 @@ class FreqtradeBot:
         # Cache values for 1800 to avoid frequent polling of the exchange for prices
         # Caching only applies to RPC methods, so prices for open trades are still
         # refreshed once every iteration.
-        self._sell_rate_cache = TTLCache(maxsize=100, ttl=1800)
-        self._buy_rate_cache = TTLCache(maxsize=100, ttl=1800)
+        self._sell_rate_cache: TTLCache = TTLCache(maxsize=100, ttl=1800)
+        self._buy_rate_cache: TTLCache = TTLCache(maxsize=100, ttl=1800)
 
         self.strategy: IStrategy = StrategyResolver.load_strategy(self.config)
 
diff --git a/freqtrade/misc.py b/freqtrade/misc.py
index 071693f8d..359d0d0e4 100644
--- a/freqtrade/misc.py
+++ b/freqtrade/misc.py
@@ -56,8 +56,8 @@ def file_dump_json(filename: Path, data: Any, is_zip: bool = False, log: bool =
         if log:
             logger.info(f'dumping json to "{filename}"')
 
-        with gzip.open(filename, 'w') as fp:
-            rapidjson.dump(data, fp, default=str, number_mode=rapidjson.NM_NATIVE)
+        with gzip.open(filename, 'w') as fpz:
+            rapidjson.dump(data, fpz, default=str, number_mode=rapidjson.NM_NATIVE)
     else:
         if log:
             logger.info(f'dumping json to "{filename}"')
diff --git a/freqtrade/pairlist/IPairList.py b/freqtrade/pairlist/IPairList.py
index 67a96cc60..6b5bd11e7 100644
--- a/freqtrade/pairlist/IPairList.py
+++ b/freqtrade/pairlist/IPairList.py
@@ -36,7 +36,7 @@ class IPairList(ABC):
         self._pairlist_pos = pairlist_pos
         self.refresh_period = self._pairlistconfig.get('refresh_period', 1800)
         self._last_refresh = 0
-        self._log_cache = TTLCache(maxsize=1024, ttl=self.refresh_period)
+        self._log_cache: TTLCache = TTLCache(maxsize=1024, ttl=self.refresh_period)
 
     @property
     def name(self) -> str:
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 316c8cb8e..33aae2dfb 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -7,7 +7,7 @@ coveralls==2.1.2
 flake8==3.8.4
 flake8-type-annotations==0.1.0
 flake8-tidy-imports==4.1.0
-mypy==0.782
+mypy==0.790
 pytest==6.1.1
 pytest-asyncio==0.14.0
 pytest-cov==2.10.1
diff --git a/requirements.txt b/requirements.txt
index 8a344a716..ef9182f3b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,6 +2,8 @@ numpy==1.19.2
 pandas==1.1.3
 
 ccxt==1.36.2
+multidict==4.7.6
+aiohttp==3.6.3
 SQLAlchemy==1.3.19
 python-telegram-bot==13.0
 arrow==0.17.0