diff --git a/cibuildwheel/macos.py b/cibuildwheel/macos.py
index ce7bd974..48ec210b 100644
--- a/cibuildwheel/macos.py
+++ b/cibuildwheel/macos.py
@@ -37,7 +37,7 @@ def get_python_configurations(build_selector: BuildSelector) -> List[PythonConfi
         PythonConfiguration(version='3.5', identifier='cp35-macosx_x86_64', url='https://www.python.org/ftp/python/3.5.4/python-3.5.4-macosx10.6.pkg'),
         PythonConfiguration(version='3.6', identifier='cp36-macosx_x86_64', url='https://www.python.org/ftp/python/3.6.8/python-3.6.8-macosx10.9.pkg'),
         PythonConfiguration(version='3.7', identifier='cp37-macosx_x86_64', url='https://www.python.org/ftp/python/3.7.8/python-3.7.8-macosx10.9.pkg'),
-        PythonConfiguration(version='3.8', identifier='cp38-macosx_x86_64', url='https://www.python.org/ftp/python/3.8.3/python-3.8.3-macosx10.9.pkg'),
+        PythonConfiguration(version='3.8', identifier='cp38-macosx_x86_64', url='https://www.python.org/ftp/python/3.8.4/python-3.8.4-macosx10.9.pkg'),
         # PyPy
         PythonConfiguration(version='2.7', identifier='pp27-macosx_x86_64', url='https://downloads.python.org/pypy/pypy2.7-v7.3.1-osx64.tar.bz2'),
         PythonConfiguration(version='3.6', identifier='pp36-macosx_x86_64', url='https://downloads.python.org/pypy/pypy3.6-v7.3.1-osx64.tar.bz2'),
diff --git a/cibuildwheel/windows.py b/cibuildwheel/windows.py
index 1baf66f5..c958b9b6 100644
--- a/cibuildwheel/windows.py
+++ b/cibuildwheel/windows.py
@@ -56,8 +56,8 @@ def get_python_configurations(build_selector: BuildSelector) -> List[PythonConfi
         PythonConfiguration(version='3.6.8', arch='64', identifier='cp36-win_amd64', url=None),
         PythonConfiguration(version='3.7.8', arch='32', identifier='cp37-win32', url=None),
         PythonConfiguration(version='3.7.8', arch='64', identifier='cp37-win_amd64', url=None),
-        PythonConfiguration(version='3.8.3', arch='32', identifier='cp38-win32', url=None),
-        PythonConfiguration(version='3.8.3', arch='64', identifier='cp38-win_amd64', url=None),
+        PythonConfiguration(version='3.8.4', arch='32', identifier='cp38-win32', url=None),
+        PythonConfiguration(version='3.8.4', arch='64', identifier='cp38-win_amd64', url=None),
         # PyPy
         PythonConfiguration(version='2.7', arch='32', identifier='pp27-win32', url='https://downloads.python.org/pypy/pypy2.7-v7.3.1-win32.zip'),
         PythonConfiguration(version='3.6', arch='32', identifier='pp36-win32', url='https://downloads.python.org/pypy/pypy3.6-v7.3.1-win32.zip'),