diff --git a/tests/test_backend_nn_ensemble.py b/tests/test_backend_nn_ensemble.py
index 73dbf4558..a6345f534 100644
--- a/tests/test_backend_nn_ensemble.py
+++ b/tests/test_backend_nn_ensemble.py
@@ -170,6 +170,17 @@ def test_nn_ensemble_is_trained(app_project):
     assert nn_ensemble.is_trained
 
 
+def test_nn_ensemble_hyperopt(app_project, fulltext_corpus):
+    nn_ensemble_type = annif.backend.get_backend('nn_ensemble')
+    nn_ensemble = nn_ensemble_type(
+        backend_id='nn_ensemble',
+        config_params={'sources': 'dummy-en'},
+        project=app_project)
+
+    optimizer = nn_ensemble.get_hp_optimizer(fulltext_corpus, metric='NDCG')
+    optimizer.optimize(n_trials=2, n_jobs=1, results_file=None)
+
+
 def test_nn_ensemble_modification_time(app_project):
     nn_ensemble_type = annif.backend.get_backend("nn_ensemble")
     nn_ensemble = nn_ensemble_type(