diff --git a/cibuildwheel/macos.py b/cibuildwheel/macos.py
index 599e9b23..b390031d 100644
--- a/cibuildwheel/macos.py
+++ b/cibuildwheel/macos.py
@@ -30,7 +30,7 @@ def get_python_configurations(build_selector):
     PythonConfiguration = namedtuple('PythonConfiguration', ['version', 'identifier', 'url'])
     python_configurations = [
         # CPython
-        PythonConfiguration(version='2.7', identifier='cp27-macosx_x86_64', url='https://www.python.org/ftp/python/2.7.17/python-2.7.17-macosx10.9.pkg'),
+        PythonConfiguration(version='2.7', identifier='cp27-macosx_x86_64', url='https://www.python.org/ftp/python/2.7.18/python-2.7.18-macosx10.9.pkg'),
         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/3.7.6/python-3.7.6-macosx10.9.pkg'),
diff --git a/cibuildwheel/windows.py b/cibuildwheel/windows.py
index e6f14ed9..a5042a77 100644
--- a/cibuildwheel/windows.py
+++ b/cibuildwheel/windows.py
@@ -36,8 +36,8 @@ def get_python_configurations(build_selector):
     PythonConfiguration = namedtuple('PythonConfiguration', ['version', 'arch', 'identifier', 'url'])
     python_configurations = [
         # CPython
-        PythonConfiguration(version='2.7.17', arch='32', identifier='cp27-win32', url=None),
-        PythonConfiguration(version='2.7.17', arch='64', identifier='cp27-win_amd64', url=None),
+        PythonConfiguration(version='2.7.18', arch='32', identifier='cp27-win32', url=None),
+        PythonConfiguration(version='2.7.18', arch='64', identifier='cp27-win_amd64', url=None),
         PythonConfiguration(version='3.5.4', arch='32', identifier='cp35-win32', url=None),
         PythonConfiguration(version='3.5.4', arch='64', identifier='cp35-win_amd64', url=None),
         PythonConfiguration(version='3.6.8', arch='32', identifier='cp36-win32', url=None),