diff --git a/tests/test_nat.py b/tests/test_nat.py
index 5bfa1a96f380..0931e2411f4a 100644
--- a/tests/test_nat.py
+++ b/tests/test_nat.py
@@ -1,4 +1,5 @@
 import time
+import pytest
 
 class TestNat(object):
     def setup_db(self, dvs):
@@ -278,6 +279,7 @@ def test_DelTwiceNaPtStaticEntry(self, dvs, testlog):
         # clear interfaces
         self.clear_interfaces(dvs)
 
+    @pytest.mark.xfail(reason="Test unstable, blocking PR builds")
     def test_VerifyConntrackTimeoutForNatEntry(self, dvs, testlog):
         # initialize
         self.setup_db(dvs)
diff --git a/tests/test_vrf.py b/tests/test_vrf.py
index f3d11c57756e..689cb38393ce 100644
--- a/tests/test_vrf.py
+++ b/tests/test_vrf.py
@@ -248,6 +248,7 @@ def test_VRFMgr_Update(self, dvs, testlog):
 
         self.vrf_remove(dvs, "Vrf_a", state)
 
+    @pytest.mark.xfail(reason="Test unstable, blocking PR builds")
     def test_VRFMgr_Capacity(self, dvs, testlog):
         self.setup_db(dvs)
 
diff --git a/tests/test_warm_reboot.py b/tests/test_warm_reboot.py
index 5ad0bc7b9b14..d961303c1c6c 100644
--- a/tests/test_warm_reboot.py
+++ b/tests/test_warm_reboot.py
@@ -2,6 +2,7 @@
 import re
 import time
 import json
+import pytest
 
 from swsscommon import swsscommon
 
@@ -1796,6 +1797,7 @@ def test_routing_WarmRestart(self, dvs, testlog):
         intf_tbl._del("{}".format(intfs[2]))
         time.sleep(2)
 
+    @pytest.mark.xfail(reason="Test unstable, blocking PR builds")
     def test_system_warmreboot_neighbor_syncup(self, dvs, testlog):
 
         appl_db = swsscommon.DBConnector(swsscommon.APPL_DB, dvs.redis_sock, 0)