diff --git a/tests/constraint_tests.py b/tests/constraint_tests.py
index 397dd2222..aeb7d26bf 100644
--- a/tests/constraint_tests.py
+++ b/tests/constraint_tests.py
@@ -280,6 +280,7 @@ def test_storage(self):
             },
             nominal_storage_capacity=1e5,
             loss_rate=0.13,
+            storage_costs=0.1,
             inflow_conversion_factor=0.97,
             outflow_conversion_factor=0.86,
             initial_storage_level=0.4,
diff --git a/tests/lp_files/storage.lp b/tests/lp_files/storage.lp
index 8135f3ecf..073f266b7 100644
--- a/tests/lp_files/storage.lp
+++ b/tests/lp_files/storage.lp
@@ -2,6 +2,10 @@
 
 min 
 objective:
++4000.0 ONE_VAR_CONSTANT
++0.1 GenericStorageBlock_storage_content(storage_no_invest_1)
++0.1 GenericStorageBlock_storage_content(storage_no_invest_2)
++0.1 GenericStorageBlock_storage_content(storage_no_invest_3)
 +56 flow(electricityBus_storage_no_invest_0_0)
 +56 flow(electricityBus_storage_no_invest_0_1)
 +56 flow(electricityBus_storage_no_invest_0_2)
@@ -51,6 +55,7 @@ c_e_GenericStorageBlock_balanced_cstr(storage_no_invest)_:
 = 40000.0
 
 bounds
+   +1 <= ONE_VAR_CONSTANT <= 1
    0 <= flow(electricityBus_storage_no_invest_0_0) <= 16667
    0 <= flow(electricityBus_storage_no_invest_0_1) <= 16667
    0 <= flow(electricityBus_storage_no_invest_0_2) <= 16667