diff --git a/src/gam.py b/src/gam.py
index 573cdf2c..3926853c 100755
--- a/src/gam.py
+++ b/src/gam.py
@@ -808,7 +808,7 @@ def getOSPlatform():
   elif myos == 'Darwin':
     myos = 'MacOS'
     mac_ver = platform.mac_ver()[0]
-    minor_ver = int(pltfrm.split('.')[1]) # pltfrm 10.14.6 == mac_ver 14
+    minor_ver = int(mac_ver.split('.')[1]) # macver 10.14.6 == minor_ver 14
     codename = MACOS_CODENAMES.get(minor_ver, '')
     pltfrm = ' '.join([codename, mac_ver])
   else: