diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 35c237837..5bafe9cb8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -100,7 +100,7 @@ jobs:
 
     - name: Mypy
       run: |
-        mypy freqtrade scripts
+        mypy freqtrade scripts tests
 
     - name: Discord notification
       uses: rjstone/discord-webhook-notify@v1
@@ -255,7 +255,7 @@ jobs:
 
     - name: Mypy
       run: |
-        mypy freqtrade scripts
+        mypy freqtrade scripts tests
 
     - name: Discord notification
       uses: rjstone/discord-webhook-notify@v1
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 0dd343bb8..d980fc4e9 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -11,7 +11,7 @@ repos:
     rev: "v0.942"
     hooks:
       - id: mypy
-        args: [ freqtrade ]
+        args: [ freqtrade, scripts, tests ]
         additional_dependencies:
           - types-cachetools==5.0.1
           - types-filelock==3.2.5
diff --git a/freqtrade/strategy/informative_decorator.py b/freqtrade/strategy/informative_decorator.py
index 0dd5320cd..7dfdf5a8c 100644
--- a/freqtrade/strategy/informative_decorator.py
+++ b/freqtrade/strategy/informative_decorator.py
@@ -23,7 +23,7 @@ class InformativeData:
 def informative(timeframe: str, asset: str = '',
                 fmt: Optional[Union[str, Callable[[Any], str]]] = None,
                 *,
-                candle_type: Optional[CandleType] = None,
+                candle_type: Optional[Union[CandleType, str]] = None,
                 ffill: bool = True) -> Callable[[PopulateIndicators], PopulateIndicators]:
     """
     A decorator for populate_indicators_Nn(self, dataframe, metadata), allowing these functions to
diff --git a/freqtrade/strategy/interface.py b/freqtrade/strategy/interface.py
index 0ec3895bc..300010b83 100644
--- a/freqtrade/strategy/interface.py
+++ b/freqtrade/strategy/interface.py
@@ -110,7 +110,7 @@ class IStrategy(ABC, HyperStrategyMixin):
     # Class level variables (intentional) containing
     # the dataprovider (dp) (access to other candles, historic data, ...)
     # and wallets - access to the current balance.
-    dp: Optional[DataProvider]
+    dp: DataProvider
     wallets: Optional[Wallets] = None
     # Filled from configuration
     stake_currency: str
diff --git a/setup.cfg b/setup.cfg
index a33ceda1f..edbd320c3 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -53,6 +53,10 @@ exclude =
 [mypy]
 ignore_missing_imports = True
 warn_unused_ignores = True
+exclude = (?x)(
+    ^build_helpers\.py$
+    )
+
 
 [mypy-tests.*]
 ignore_errors = True