diff --git a/cloudkitty/storage/v2/elasticsearch/client.py b/cloudkitty/storage/v2/elasticsearch/client.py
index 98dc8a29..eb87934e 100644
--- a/cloudkitty/storage/v2/elasticsearch/client.py
+++ b/cloudkitty/storage/v2/elasticsearch/client.py
@@ -78,6 +78,9 @@ class ElasticsearchClient(object):
             must.append({'term': {'type': filters['type']}})
 
         if metric_types:
+            if type(metric_types) is not list:
+                metric_types = [metric_types]
+
             must.append({"terms": {"type": metric_types}})
 
         return must
diff --git a/cloudkitty/storage/v2/opensearch/client.py b/cloudkitty/storage/v2/opensearch/client.py
index 868af2c4..b46122e4 100644
--- a/cloudkitty/storage/v2/opensearch/client.py
+++ b/cloudkitty/storage/v2/opensearch/client.py
@@ -78,6 +78,9 @@ class OpenSearchClient(object):
             must.append({'term': {'type': filters['type']}})
 
         if metric_types:
+            if type(metric_types) is not list:
+                metric_types = [metric_types]
+
             must.append({"terms": {"type": metric_types}})
 
         return must
diff --git a/cloudkitty/tests/storage/v2/elasticsearch/test_client.py b/cloudkitty/tests/storage/v2/elasticsearch/test_client.py
index 5d3158b4..c3493574 100644
--- a/cloudkitty/tests/storage/v2/elasticsearch/test_client.py
+++ b/cloudkitty/tests/storage/v2/elasticsearch/test_client.py
@@ -53,6 +53,13 @@ class TestElasticsearchClient(unittest.TestCase):
             [{'term': {'type': 'awesome'}}],
         )
 
+    def test_build_must_with_metric_type(self):
+        types = 'awesome'
+        self.assertEqual(
+            self.client._build_must(None, None, types, None),
+            [{'terms': {'type': ['awesome']}}],
+        )
+
     def test_build_must_with_metric_types(self):
         types = ['awesome', 'amazing']
         self.assertEqual(
diff --git a/cloudkitty/tests/storage/v2/opensearch/test_client.py b/cloudkitty/tests/storage/v2/opensearch/test_client.py
index b33515c6..b3c2ae7a 100644
--- a/cloudkitty/tests/storage/v2/opensearch/test_client.py
+++ b/cloudkitty/tests/storage/v2/opensearch/test_client.py
@@ -53,6 +53,13 @@ class TestOpenSearchClient(unittest.TestCase):
             [{'term': {'type': 'awesome'}}],
         )
 
+    def test_build_must_with_metric_type(self):
+        types = 'awesome'
+        self.assertEqual(
+            self.client._build_must(None, None, types, None),
+            [{'terms': {'type': ['awesome']}}],
+        )
+
     def test_build_must_with_metric_types(self):
         types = ['awesome', 'amazing']
         self.assertEqual(
diff --git a/releasenotes/notes/fix-elasticsearch-a9a37443f81b3a79.yaml b/releasenotes/notes/fix-elasticsearch-a9a37443f81b3a79.yaml
new file mode 100644
index 00000000..7568dbfb
--- /dev/null
+++ b/releasenotes/notes/fix-elasticsearch-a9a37443f81b3a79.yaml
@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fix request to Elasticsearch/OpenSearch that has potentially not the 
+    correct type.