diff --git a/python/samba/tests/posixacl.py b/python/samba/tests/posixacl.py
index 38f578e0d35..462ee7ef12d 100644
--- a/python/samba/tests/posixacl.py
+++ b/python/samba/tests/posixacl.py
@@ -28,6 +28,8 @@ import os
 from samba.samba3 import smbd, passdb
 from samba.samba3 import param as s3param
 
+DOM_SID = "S-1-5-21-2212615479-2695158682-2101375467"
+
 
 class PosixAclMappingTests(TestCaseInTempDir):
 
@@ -44,18 +46,18 @@ class PosixAclMappingTests(TestCaseInTempDir):
 
     def test_setntacl(self):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=False)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=False)
 
     def test_setntacl_smbd_getntacl(self):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=True)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=True)
         facl = getntacl(self.lp, self.tempf, direct_db_access=True)
         anysid = security.dom_sid(security.SID_NT_SELF)
         self.assertEquals(facl.as_sddl(anysid),acl)
 
     def test_setntacl_smbd_setposixacl_getntacl(self):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=True)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=True)
 
         # This will invalidate the ACL, as we have a hook!
         smbd.set_simple_acl(self.tempf, 0o640)
@@ -69,7 +71,7 @@ class PosixAclMappingTests(TestCaseInTempDir):
 
     def test_setntacl_invalidate_getntacl(self):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=True)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=True)
 
         # This should invalidate the ACL, as we include the posix ACL in the hash
         (backend_obj, dbname) = checkset_backend(self.lp, None, None)
@@ -83,7 +85,7 @@ class PosixAclMappingTests(TestCaseInTempDir):
 
     def test_setntacl_invalidate_getntacl_smbd(self):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=False)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=False)
 
         # This should invalidate the ACL, as we include the posix ACL in the hash
         (backend_obj, dbname) = checkset_backend(self.lp, None, None)
@@ -99,7 +101,7 @@ class PosixAclMappingTests(TestCaseInTempDir):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
         simple_acl_from_posix = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)(A;;0x001200a9;;;S-1-5-21-2212615479-2695158682-2101375467-513)(A;;;;;WD)"
         os.chmod(self.tempf, 0o750)
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=False)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=False)
 
         # This should invalidate the ACL, as we include the posix ACL in the hash
         (backend_obj, dbname) = checkset_backend(self.lp, None, None)
@@ -113,14 +115,14 @@ class PosixAclMappingTests(TestCaseInTempDir):
 
     def test_setntacl_getntacl_smbd(self):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=True)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=True)
         facl = getntacl(self.lp, self.tempf, direct_db_access=False)
         anysid = security.dom_sid(security.SID_NT_SELF)
         self.assertEquals(facl.as_sddl(anysid),acl)
 
     def test_setntacl_smbd_getntacl_smbd(self):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=False)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=False)
         facl = getntacl(self.lp, self.tempf, direct_db_access=False)
         anysid = security.dom_sid(security.SID_NT_SELF)
         self.assertEquals(facl.as_sddl(anysid),acl)
@@ -128,7 +130,7 @@ class PosixAclMappingTests(TestCaseInTempDir):
     def test_setntacl_smbd_setposixacl_getntacl_smbd(self):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
         simple_acl_from_posix = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;;0x001f019f;;;S-1-5-21-2212615479-2695158682-2101375467-512)(A;;0x00120089;;;S-1-5-21-2212615479-2695158682-2101375467-513)(A;;;;;WD)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=False)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=False)
         # This invalidates the hash of the NT acl just set because there is a hook in the posix ACL set code
         smbd.set_simple_acl(self.tempf, 0o640)
         facl = getntacl(self.lp, self.tempf, direct_db_access=False)
@@ -139,7 +141,7 @@ class PosixAclMappingTests(TestCaseInTempDir):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
         BA_sid = security.dom_sid(security.SID_BUILTIN_ADMINISTRATORS)
         simple_acl_from_posix = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;;0x001f019f;;;S-1-5-21-2212615479-2695158682-2101375467-512)(A;;0x00120089;;;BA)(A;;0x00120089;;;S-1-5-21-2212615479-2695158682-2101375467-513)(A;;;;;WD)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=False)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=False)
         # This invalidates the hash of the NT acl just set because there is a hook in the posix ACL set code
         s4_passdb = passdb.PDB(self.lp.get("passdb backend"))
         (BA_gid,BA_type) = s4_passdb.sid_to_id(BA_sid)
@@ -152,14 +154,14 @@ class PosixAclMappingTests(TestCaseInTempDir):
 
     def test_setntacl_smbd_getntacl_smbd_gpo(self):
         acl = "O:DAG:DUD:P(A;OICI;0x001f01ff;;;DA)(A;OICI;0x001f01ff;;;EA)(A;OICIIO;0x001f01ff;;;CO)(A;OICI;0x001f01ff;;;DA)(A;OICI;0x001f01ff;;;SY)(A;OICI;0x001200a9;;;AU)(A;OICI;0x001200a9;;;ED)S:AI(OU;CIIDSA;WP;f30e3bbe-9ff0-11d1-b603-0000f80367c1;bf967aa5-0de6-11d0-a285-00aa003049e2;WD)(OU;CIIDSA;WP;f30e3bbf-9ff0-11d1-b603-0000f80367c1;bf967aa5-0de6-11d0-a285-00aa003049e2;WD)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=False)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=False)
         facl = getntacl(self.lp, self.tempf, direct_db_access=False)
-        domsid = security.dom_sid("S-1-5-21-2212615479-2695158682-2101375467")
+        domsid = security.dom_sid(DOM_SID)
         self.assertEquals(facl.as_sddl(domsid),acl)
 
     def test_setntacl_getposixacl(self):
         acl = "O:S-1-5-21-2212615479-2695158682-2101375467-512G:S-1-5-21-2212615479-2695158682-2101375467-513D:(A;OICI;0x001f01ff;;;S-1-5-21-2212615479-2695158682-2101375467-512)"
-        setntacl(self.lp, self.tempf, acl, "S-1-5-21-2212615479-2695158682-2101375467", use_ntvfs=False)
+        setntacl(self.lp, self.tempf, acl, DOM_SID, use_ntvfs=False)
         facl = getntacl(self.lp, self.tempf)
         anysid = security.dom_sid(security.SID_NT_SELF)
         self.assertEquals(facl.as_sddl(anysid),acl)