diff --git a/hera_mc/mc_session.py b/hera_mc/mc_session.py
index 8e99e8527..7ecb2f514 100644
--- a/hera_mc/mc_session.py
+++ b/hera_mc/mc_session.py
@@ -4618,7 +4618,7 @@ def add_antenna_status_from_corrcm(self, ant_status_dict=None,
 
     def add_ant_metric(self, obsid, ant, pol, metric, val):
         """
-        Add a new antenna metric to the M&C database.
+        Add a new antenna metric or update an existing metric.
 
         Parameters
         ----------
@@ -4636,7 +4636,8 @@ def add_ant_metric(self, obsid, ant, pol, metric, val):
         """
         db_time = self.get_current_db_time()
 
-        self.add(AntMetrics.create(obsid, ant, pol, metric, db_time, val))
+        obj_list = [AntMetrics.create(obsid, ant, pol, metric, db_time, val)]
+        self._insert_ignoring_duplicates(AntMetrics, obj_list, update=True)
 
     def get_ant_metric(self, ant=None, pol=None, metric=None, starttime=None,
                        stoptime=None):
@@ -4681,7 +4682,7 @@ def get_ant_metric(self, ant=None, pol=None, metric=None, starttime=None,
 
     def add_array_metric(self, obsid, metric, val):
         """
-        Add a new array metric to the M&C database.
+        Add a new array metric or update an existing metric.
 
         Parameters
         ----------
@@ -4695,7 +4696,8 @@ def add_array_metric(self, obsid, metric, val):
         """
         db_time = self.get_current_db_time()
 
-        self.add(ArrayMetrics.create(obsid, metric, db_time, val))
+        obj_list = [ArrayMetrics.create(obsid, metric, db_time, val)]
+        self._insert_ignoring_duplicates(ArrayMetrics, obj_list, update=True)
 
     def get_array_metric(self, metric=None, starttime=None, stoptime=None):
         """
diff --git a/hera_mc/tests/test_qm.py b/hera_mc/tests/test_qm.py
index 601f59d06..a4de9394e 100644
--- a/hera_mc/tests/test_qm.py
+++ b/hera_mc/tests/test_qm.py
@@ -44,12 +44,22 @@ def test_AntMetrics(mcsession, pol_x, pol_y):
 
     # now the tests
     test_session.add_ant_metric(obsid, 0, pol_x, 'test', 4.5)
+    test_session.commit()
     r = test_session.get_ant_metric(metric='test')
     assert len(r) == 1
     assert r[0].antpol == (0, pol_x)
     assert r[0].metric == 'test'
     assert r[0].val == 4.5
 
+    # test that updating works
+    test_session.add_ant_metric(obsid, 0, pol_x, 'test', 4.3)
+    test_session.commit()
+    r = test_session.get_ant_metric(metric='test')
+    assert len(r) == 1
+    assert r[0].antpol == (0, pol_x)
+    assert r[0].metric == 'test'
+    assert r[0].val == 4.3
+
     # Test more exciting queries
     test_session.add_ant_metric(obsid, 0, pol_y, 'test', 2.5)
     test_session.add_ant_metric(obsid, 3, pol_x, 'test', 2.5)
@@ -152,10 +162,18 @@ def test_ArrayMetrics(mcsession):
 
     # now the tests
     test_session.add_array_metric(obsid, 'test', 6.2)
+    test_session.commit()
     r = test_session.get_array_metric()
     assert r[0].metric == 'test'
     assert r[0].val == 6.2
 
+    # test that updating works
+    test_session.add_array_metric(obsid, 'test', 6.5)
+    test_session.commit()
+    r = test_session.get_array_metric()
+    assert r[0].metric == 'test'
+    assert r[0].val == 6.5
+
     # Test more exciting queries
     test_session.add_array_metric(obsid + 10, 'test', 2.5)
     test_session.add_array_metric(obsid - 10, 'test', 2.5)