diff --git a/src/gam.py b/src/gam.py
index 569e1a12..fe1807a0 100755
--- a/src/gam.py
+++ b/src/gam.py
@@ -6966,6 +6966,9 @@ def getUserAttributes(i, cd, updateCmd):
         elif myopt in [u'username', u'name']:
           posix[u'username'] = sys.argv[i+1]
           i += 2
+        elif myopt in [u'os', u'operatingsystemtype']:
+          posix[u'operatingSystemType'] = sys.argv[i+1]
+          i += 2
         elif myopt in [u'endposix']:
           i += 1
           break