diff --git a/cosima_cookbook/database_update.py b/cosima_cookbook/database_update.py
index 4182328e..a0785833 100755
--- a/cosima_cookbook/database_update.py
+++ b/cosima_cookbook/database_update.py
@@ -4,7 +4,7 @@
 import cosima_cookbook as cc
 
 
-def main():
+def main(argv=None):
     parser = argparse.ArgumentParser(description="Update COSIMA cookbook database.")
     parser.add_argument(
         "dirs", type=pathlib.Path, nargs="+", help="Directories to index."
@@ -17,7 +17,7 @@ def main():
         default="cosima_master.db",
         help="Database to update.",
     )
-    args = parser.parse_args()
+    args = parser.parse_args(argv)
 
     print(cc)
 
diff --git a/test/data/update/experiment_a/test1.nc b/test/data/update/experiment_a/test1.nc
new file mode 100644
index 00000000..27f5ea7b
Binary files /dev/null and b/test/data/update/experiment_a/test1.nc differ
diff --git a/test/data/update/experiment_b/test2.nc b/test/data/update/experiment_b/test2.nc
new file mode 100644
index 00000000..d3498cc5
Binary files /dev/null and b/test/data/update/experiment_b/test2.nc differ
diff --git a/test/test_indexing.py b/test/test_indexing.py
index 6855e1e5..67129094 100644
--- a/test/test_indexing.py
+++ b/test/test_indexing.py
@@ -38,7 +38,7 @@ def test_find_files():
 
     # Test works with alternative suffix
     files = database.find_files("test/", "*.py")
-    assert len(files) == 8
+    assert len(files) == 9
 
     for f in files:
         assert Path(f).suffix == ".py"
diff --git a/test/test_update.py b/test/test_update.py
new file mode 100644
index 00000000..998d470a
--- /dev/null
+++ b/test/test_update.py
@@ -0,0 +1,13 @@
+import shlex
+from cosima_cookbook import database_update
+
+
+def test_database_update(tmpdir):
+
+    args = shlex.split(
+        "-db {db} test/data/update/experiment_a test/data/update/experiment_b".format(
+            db=tmpdir.join("test.db")
+        )
+    )
+
+    database_update.main(args)