diff --git a/setup.cfg b/setup.cfg
index 60e866562cd..40faad55a2e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -64,7 +64,7 @@ formats = sdist.tgz,bdist_wheel
 
 [mypy]
 ignore_missing_imports = True
-no_implicit_optional = True
+no_implicit_optional = False
 strict_equality = True
 warn_redundant_casts = True
 warn_return_any = True
diff --git a/src/_pytest/_code/code.py b/src/_pytest/_code/code.py
index 694f45fb6d4..a0ffecd607f 100644
--- a/src/_pytest/_code/code.py
+++ b/src/_pytest/_code/code.py
@@ -403,9 +403,7 @@ class ExceptionInfo(Generic[_E]):
 
     @classmethod
     def from_exc_info(
-        cls,
-        exc_info: Tuple["Type[_E]", "_E", TracebackType],
-        exprinfo: Optional[str] = None,
+        cls, exc_info: Tuple["Type[_E]", "_E", TracebackType], exprinfo: str = None
     ) -> "ExceptionInfo[_E]":
         """returns an ExceptionInfo for an existing exc_info tuple.
 
@@ -429,9 +427,7 @@ def from_exc_info(
         return cls(exc_info, _striptext)
 
     @classmethod
-    def from_current(
-        cls, exprinfo: Optional[str] = None
-    ) -> "ExceptionInfo[BaseException]":
+    def from_current(cls, exprinfo: str = None) -> "ExceptionInfo[BaseException]":
         """returns an ExceptionInfo matching the current traceback
 
         .. warning::
diff --git a/src/_pytest/config/findpaths.py b/src/_pytest/config/findpaths.py
index f06c9cfffb1..bcf56b10273 100644
--- a/src/_pytest/config/findpaths.py
+++ b/src/_pytest/config/findpaths.py
@@ -1,6 +1,5 @@
 import os
 from typing import List
-from typing import Optional
 
 import py
 
@@ -108,10 +107,7 @@ def get_dir_from_path(path):
 
 
 def determine_setup(
-    inifile: str,
-    args: List[str],
-    rootdir_cmd_arg: Optional[str] = None,
-    config: Optional["Config"] = None,
+    inifile: str, args: List[str], rootdir_cmd_arg: str = None, config: "Config" = None
 ):
     dirs = get_dirs_from_args(args)
     if inifile:
diff --git a/src/_pytest/outcomes.py b/src/_pytest/outcomes.py
index 94713662571..0beeced0df7 100644
--- a/src/_pytest/outcomes.py
+++ b/src/_pytest/outcomes.py
@@ -17,7 +17,7 @@ class OutcomeException(BaseException):
         contain info about test and collection outcomes.
     """
 
-    def __init__(self, msg: Optional[str] = None, pytrace: bool = True) -> None:
+    def __init__(self, msg: str = None, pytrace: bool = True) -> None:
         if msg is not None and not isinstance(msg, str):
             error_msg = (
                 "{} expected string as 'msg' parameter, got '{}' instead.\n"
@@ -45,10 +45,7 @@ class Skipped(OutcomeException):
     __module__ = "builtins"
 
     def __init__(
-        self,
-        msg: Optional[str] = None,
-        pytrace: bool = True,
-        allow_module_level: bool = False,
+        self, msg: str = None, pytrace: bool = True, allow_module_level: bool = False
     ) -> None:
         OutcomeException.__init__(self, msg=msg, pytrace=pytrace)
         self.allow_module_level = allow_module_level
@@ -63,9 +60,7 @@ class Failed(OutcomeException):
 class Exit(Exception):
     """ raised for immediate program exits (no tracebacks/summaries)"""
 
-    def __init__(
-        self, msg: str = "unknown reason", returncode: Optional[int] = None
-    ) -> None:
+    def __init__(self, msg: str = "unknown reason", returncode: int = None) -> None:
         self.msg = msg
         self.returncode = returncode
         super().__init__(msg)
@@ -74,7 +69,7 @@ def __init__(
 # exposed helper methods
 
 
-def exit(msg: str, returncode: Optional[int] = None) -> "NoReturn":
+def exit(msg: str, returncode: int = None) -> "NoReturn":
     """
     Exit testing process.
 
@@ -155,7 +150,7 @@ def xfail(reason: str = "") -> "NoReturn":
 
 
 def importorskip(
-    modname: str, minversion: Optional[str] = None, reason: Optional[str] = None
+    modname: str, minversion: str = None, reason: Optional[str] = None
 ) -> Any:
     """Imports and returns the requested module ``modname``, or skip the
     current test if the module cannot be imported.
diff --git a/src/_pytest/python_api.py b/src/_pytest/python_api.py
index f03d45ab76c..bffda93a908 100644
--- a/src/_pytest/python_api.py
+++ b/src/_pytest/python_api.py
@@ -567,7 +567,7 @@ def raises(
 def raises(  # noqa: F811
     expected_exception: Union["Type[_E]", Tuple["Type[_E]", ...]],
     *args: Any,
-    match: Optional[Union[str, "Pattern"]] = None,
+    match: Union[str, "Pattern"] = None,
     **kwargs: Any
 ) -> Union["RaisesContext[_E]", Optional[_pytest._code.ExceptionInfo[_E]]]:
     r"""
@@ -725,7 +725,7 @@ def __init__(
         self,
         expected_exception: Union["Type[_E]", Tuple["Type[_E]", ...]],
         message: str,
-        match_expr: Optional[Union[str, "Pattern"]] = None,
+        match_expr: Union[str, "Pattern"] = None,
     ) -> None:
         self.expected_exception = expected_exception
         self.message = message
diff --git a/src/_pytest/recwarn.py b/src/_pytest/recwarn.py
index 58076d66b9d..b5f3c723281 100644
--- a/src/_pytest/recwarn.py
+++ b/src/_pytest/recwarn.py
@@ -77,7 +77,7 @@ def warns(
 def warns(  # noqa: F811
     expected_warning: Union["Type[Warning]", Tuple["Type[Warning]", ...]],
     *args: Any,
-    match: Optional[Union[str, "Pattern"]] = None,
+    match: Union[str, "Pattern"] = None,
     **kwargs: Any
 ) -> Union["WarningsChecker", Any]:
     r"""Assert that code raises a particular class of warning.
@@ -207,7 +207,7 @@ def __init__(
         expected_warning: Optional[
             Union["Type[Warning]", Tuple["Type[Warning]", ...]]
         ] = None,
-        match_expr: Optional[Union[str, "Pattern"]] = None,
+        match_expr: Union[str, "Pattern"] = None,
     ) -> None:
         super().__init__()