diff --git a/.gitignore b/.gitignore
index 93813ae0e..cc0a449b0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -37,6 +37,9 @@ docs/_build
 pip-log.txt
 pip-delete-this-directory.txt
 
+# dotenv environment variables file
+.env*
+
 # Unit test / coverage reports
 htmlcov/
 .tox/
diff --git a/databroker/mongo_normalized.py b/databroker/mongo_normalized.py
index 844e9eb51..92a7b5a69 100644
--- a/databroker/mongo_normalized.py
+++ b/databroker/mongo_normalized.py
@@ -643,6 +643,9 @@ def __init__(
     def metadata(self):
         return self._metadata
 
+    def structure(self):
+        return None
+
     def keys(self):
         return self._contents.keys()
 
@@ -1418,6 +1421,9 @@ def metadata(self):
         "Metadata about this MongoAdapter."
         return self._metadata
 
+    def structure(self):
+        return None
+
     @property
     def sorting(self):
         return list(self._sorting)
diff --git a/databroker/tests/utils.py b/databroker/tests/utils.py
index 2f94e89da..0b259828e 100644
--- a/databroker/tests/utils.py
+++ b/databroker/tests/utils.py
@@ -120,5 +120,6 @@ def delete_fs():
     request.addfinalizer(delete_fs)
 
     # Create indexes.
-    suitcase.mongo_normalized.Serializer(mds._db, fs._db)
+    serializer = suitcase.mongo_normalized.Serializer(mds._db, fs._db)
+    serializer.create_indexes()
     return v0.Broker(mds, fs)
diff --git a/requirements-test.txt b/requirements-test.txt
index 582a302e3..274cd56a4 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -3,6 +3,7 @@ bluesky
 codecov
 coverage
 flake8
+glue-core <1.18
 glueviz
 matplotlib
 mongomock