diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 93aaf6b37..4bf290456 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -93,6 +93,6 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install -U pip
-          pip install -U mypy==0.790
+          pip install -U git+git://github.com/python/mypy@af3c8be98f
       - name: Run stubtest
         run: python tests/stubtest_test.py --ignore-unused-whitelist
diff --git a/tests/stubtest_whitelists/py36.txt b/tests/stubtest_whitelists/py36.txt
index b30b37d5b..9f56f014c 100644
--- a/tests/stubtest_whitelists/py36.txt
+++ b/tests/stubtest_whitelists/py36.txt
@@ -24,6 +24,7 @@ copy.PyStringMap
 ctypes.CDLL.__init__
 email.message.MIMEPart.as_string
 enum.Enum._generate_next_value_
+fractions.Fraction.__new__  # overload is too complicated for stubtest to resolve
 hmac.HMAC.__init__
 importlib.metadata
 importlib.resources
@@ -80,4 +81,4 @@ socket.MsgFlag.__new__
 ssl.Options.__new__
 ssl.VerifyFlags.__new__
 ssl.VerifyMode.__new__
-tkinter.EventType.__new__
\ No newline at end of file
+tkinter.EventType.__new__
diff --git a/tests/stubtest_whitelists/py37.txt b/tests/stubtest_whitelists/py37.txt
index 9a956a4b1..b3070038b 100644
--- a/tests/stubtest_whitelists/py37.txt
+++ b/tests/stubtest_whitelists/py37.txt
@@ -29,6 +29,7 @@ dataclasses.Field.__init__
 dataclasses.field
 email.message.MIMEPart.as_string
 enum.Enum._generate_next_value_
+fractions.Fraction.__new__  # overload is too complicated for stubtest to resolve
 hmac.HMAC.__init__
 http.client.HTTPSConnection.__init__
 http.server.SimpleHTTPRequestHandler.__init__
@@ -77,4 +78,4 @@ ssl.Options.__new__
 ssl.TLSVersion.__new__
 ssl.VerifyFlags.__new__
 ssl.VerifyMode.__new__
-tkinter.EventType.__new__
\ No newline at end of file
+tkinter.EventType.__new__
diff --git a/tests/stubtest_whitelists/py38.txt b/tests/stubtest_whitelists/py38.txt
index e8c166748..bb0c30bac 100644
--- a/tests/stubtest_whitelists/py38.txt
+++ b/tests/stubtest_whitelists/py38.txt
@@ -39,6 +39,7 @@ dataclasses.InitVar.__init__
 dataclasses.field
 email.message.MIMEPart.as_string
 enum.Enum._generate_next_value_
+fractions.Fraction.__new__  # overload is too complicated for stubtest to resolve
 functools.partialmethod.__get__
 functools.singledispatchmethod.__call__  # A lie to reflect that the descriptor get returns a callable
 gettext.install
@@ -110,4 +111,4 @@ ssl.Options.__new__
 ssl.TLSVersion.__new__
 ssl.VerifyFlags.__new__
 ssl.VerifyMode.__new__
-tkinter.EventType.__new__
\ No newline at end of file
+tkinter.EventType.__new__
diff --git a/tests/stubtest_whitelists/py39.txt b/tests/stubtest_whitelists/py39.txt
index a82080ecd..949245769 100644
--- a/tests/stubtest_whitelists/py39.txt
+++ b/tests/stubtest_whitelists/py39.txt
@@ -42,6 +42,7 @@ dataclasses.field
 dummy_threading
 email.message.MIMEPart.as_string
 enum.Enum._generate_next_value_
+fractions.Fraction.__new__  # overload is too complicated for stubtest to resolve
 ftplib.FTP.__init__
 ftplib.FTP_TLS.__init__
 functools.partialmethod.__get__