diff --git a/Lib/_osx_support.py b/Lib/_osx_support.py
index aa66c8b9f4..0cb064fcd7 100644
--- a/Lib/_osx_support.py
+++ b/Lib/_osx_support.py
@@ -507,6 +507,11 @@ def get_platform_osx(_config_vars, osname, release, machine):
     # MACOSX_DEPLOYMENT_TARGET.
 
     macver = _config_vars.get('MACOSX_DEPLOYMENT_TARGET', '')
+    if macver and '.' not in macver:
+        # Ensure that the version includes at least a major
+        # and minor version, even if MACOSX_DEPLOYMENT_TARGET
+        # is set to a single-label version like "14".
+        macver += '.0'
     macrelease = _get_system_version() or macver
     macver = macver or macrelease