diff --git a/models/answer.py b/models/answer.py
index 688f941..e34680f 100644
--- a/models/answer.py
+++ b/models/answer.py
@@ -83,7 +83,9 @@ class SelectorValue(BaseValue):
             raise ValueError(AnswerError.TOO_MANY_SELECTED.value)
 
 
-Value = Annotated[Union[SelectorValue, TextValue, ScaleValue], Field(discriminator='question_type')]
+Value = Annotated[
+    Union[SelectorValue, TextValue, ScaleValue], Field(discriminator="question_type")
+]
 
 
 class AnswerData(BaseModel):
diff --git a/models/form.py b/models/form.py
index 0cf199f..ca65223 100644
--- a/models/form.py
+++ b/models/form.py
@@ -131,7 +131,10 @@ class SelectorQuestion(BaseQuestion):
         return v
 
 
-Question = Annotated[Union[SelectorQuestion, TextQuestion, ScaleQuestion], Field(discriminator='question_type')]
+Question = Annotated[
+    Union[SelectorQuestion, TextQuestion, ScaleQuestion],
+    Field(discriminator="question_type"),
+]
 
 
 class Page(BaseModel):