diff --git a/armada/handlers/override.py b/armada/handlers/override.py
index 8e48a70a..3fd35d30 100644
--- a/armada/handlers/override.py
+++ b/armada/handlers/override.py
@@ -43,6 +43,8 @@ class Override(object):
             if isinstance(v, collections.Mapping):
                 r = self.update(d.get(k, {}), v)
                 d[k] = r
+            elif isinstance(v, str) and isinstance(d.get(k), (list, tuple)):
+                d[k] = [x.strip() for x in v.split(',')]
             else:
                 d[k] = u[k]
         return d
@@ -140,7 +142,6 @@ class Override(object):
             for value in self.values:
                 merging_values = self._load_yaml_file(value)
                 self.update_document(merging_values)
-
         if self.overrides:
             for override in self.overrides:
                 new_value = override.split('=')[1]
diff --git a/armada/tests/unit/handlers/templates/override-03-expected.yaml b/armada/tests/unit/handlers/templates/override-03-expected.yaml
new file mode 100644
index 00000000..7a1a2057
--- /dev/null
+++ b/armada/tests/unit/handlers/templates/override-03-expected.yaml
@@ -0,0 +1,10 @@
+---
+schema: armada/Manifest/v1
+metadata:
+  schema: metadata/Document/v1
+  name: simple-armada
+data:
+  release_prefix: armada
+  chart_groups:
+    - blog-group3
+    - blog-group4
diff --git a/armada/tests/unit/handlers/test_override.py b/armada/tests/unit/handlers/test_override.py
index c40ea88b..867ba879 100644
--- a/armada/tests/unit/handlers/test_override.py
+++ b/armada/tests/unit/handlers/test_override.py
@@ -62,6 +62,21 @@ class OverrideTestCase(unittest.TestCase):
 
             self.assertEqual(ovr_doc, expect_doc)
 
+    def test_set_list_valid(self):
+        expected = "{}/templates/override-{}-expected.yaml".format(
+            self.basepath, '03')
+
+        with open(self.base_manifest) as f, open(expected) as e:
+            doc_obj = list(yaml.safe_load_all(f.read()))
+            doc_path = ['manifest', 'simple-armada']
+            override = ('manifest:simple-armada:chart_groups=\
+                         blog-group3,blog-group4',)
+            ovr = Override(doc_obj, override)
+            ovr.update_manifests()
+            ovr_doc = ovr.find_manifest_document(doc_path)
+            expect_doc = list(yaml.load_all(e.read()))[0]
+            self.assertEqual(expect_doc, ovr_doc)
+
     def test_find_manifest_document_valid(self):
         expected = "{}/templates/override-{}-expected.yaml".format(
             self.basepath, '02')