diff --git a/graphene/types/inputobjecttype.py b/graphene/types/inputobjecttype.py
index fdf38ba0..257f48be 100644
--- a/graphene/types/inputobjecttype.py
+++ b/graphene/types/inputobjecttype.py
@@ -1,11 +1,12 @@
+from typing import TYPE_CHECKING
+
 from .base import BaseOptions, BaseType
 from .inputfield import InputField
 from .unmountedtype import UnmountedType
 from .utils import yank_fields_from_attrs
 
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from typing import Dict, Callable  # NOQA
 
 
diff --git a/graphene/types/interface.py b/graphene/types/interface.py
index 6503b78b..31bcc7f9 100644
--- a/graphene/types/interface.py
+++ b/graphene/types/interface.py
@@ -1,10 +1,11 @@
+from typing import TYPE_CHECKING
+
 from .base import BaseOptions, BaseType
 from .field import Field
 from .utils import yank_fields_from_attrs
 
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from typing import Dict, Iterable, Type  # NOQA
 
 
diff --git a/graphene/types/mutation.py b/graphene/types/mutation.py
index ad47c62a..2de21b36 100644
--- a/graphene/types/mutation.py
+++ b/graphene/types/mutation.py
@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from ..utils.deprecated import warn_deprecation
 from ..utils.get_unbound_function import get_unbound_function
 from ..utils.props import props
@@ -6,9 +8,8 @@ from .objecttype import ObjectType, ObjectTypeOptions
 from .utils import yank_fields_from_attrs
 from .interface import Interface
 
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from .argument import Argument  # NOQA
     from typing import Dict, Type, Callable, Iterable  # NOQA
 
diff --git a/graphene/types/objecttype.py b/graphene/types/objecttype.py
index 1ff29a2e..b3b829fe 100644
--- a/graphene/types/objecttype.py
+++ b/graphene/types/objecttype.py
@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from .base import BaseOptions, BaseType, BaseTypeMeta
 from .field import Field
 from .interface import Interface
@@ -7,9 +9,8 @@ try:
     from dataclasses import make_dataclass, field
 except ImportError:
     from ..pyutils.dataclasses import make_dataclass, field  # type: ignore
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from typing import Dict, Iterable, Type  # NOQA
 
 
diff --git a/graphene/types/union.py b/graphene/types/union.py
index f77e833a..b7c5dc62 100644
--- a/graphene/types/union.py
+++ b/graphene/types/union.py
@@ -1,9 +1,10 @@
+from typing import TYPE_CHECKING
+
 from .base import BaseOptions, BaseType
 from .unmountedtype import UnmountedType
 
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from .objecttype import ObjectType  # NOQA
     from typing import Iterable, Type  # NOQA