diff --git a/python/samba/gp/gp_cert_auto_enroll_ext.py b/python/samba/gp/gp_cert_auto_enroll_ext.py
index 9b743cb7f9b..8d6d1e86d17 100644
--- a/python/samba/gp/gp_cert_auto_enroll_ext.py
+++ b/python/samba/gp/gp_cert_auto_enroll_ext.py
@@ -54,11 +54,11 @@ global_trust_dirs = ['/etc/pki/trust/anchors',           # SUSE
 
 def octet_string_to_objectGUID(data):
     """Convert an octet string to an objectGUID."""
-    return '%s-%s-%s-%s-%s' % ('%02x' % struct.unpack('<L', data[0:4])[0],
-                               '%02x' % struct.unpack('<H', data[4:6])[0],
-                               '%02x' % struct.unpack('<H', data[6:8])[0],
-                               '%02x' % struct.unpack('>H', data[8:10])[0],
-                               '%02x%02x' % struct.unpack('>HL', data[10:]))
+    return '%s-%s-%s-%s-%s' % (('%02x' % struct.unpack('<L', data[0:4])[0]).zfill(8),
+                               ('%02x' % struct.unpack('<H', data[4:6])[0]).zfill(4),
+                               ('%02x' % struct.unpack('<H', data[6:8])[0]).zfill(4),
+                               ('%02x' % struct.unpack('>H', data[8:10])[0]).zfill(4),
+                               ('%02x%02x' % struct.unpack('>HL', data[10:])).zfill(12))
 
 
 def group_and_sort_end_point_information(end_point_information):