diff --git a/src/script_interface/walberla/EKContainer.hpp b/src/script_interface/walberla/EKContainer.hpp
index b52928ae37..15a8a19378 100644
--- a/src/script_interface/walberla/EKContainer.hpp
+++ b/src/script_interface/walberla/EKContainer.hpp
@@ -60,9 +60,15 @@ class EKContainer : public ObjectList<EKSpecies> {
     add_parameters({
         {"tau",
          [this](Variant const &v) {
+           auto const tau = get_value<double>(v);
+           context()->parallel_try_catch([tau]() {
+             if (tau <= 0.) {
+               throw std::domain_error("Parameter 'tau' must be > 0");
+             }
+           });
            EK::ek_container.set_tau(get_value<double>(v));
          },
-         [this]() { return EK::ek_container.get_tau(); }},
+         []() { return EK::ek_container.get_tau(); }},
         {"solver", [this](Variant const &v) { set_solver(v); },
          [this]() { return get_solver(); }},
     });
diff --git a/testsuite/python/ek_interface.py b/testsuite/python/ek_interface.py
index c5ee924710..eed2eb1280 100644
--- a/testsuite/python/ek_interface.py
+++ b/testsuite/python/ek_interface.py
@@ -55,6 +55,7 @@ def setUp(self):
             n_ghost_layers=1, agrid=self.params["agrid"])
         ek_solver = espressomd.electrokinetics.EKNone(lattice=self.lattice)
         self.system.ekcontainer.solver = ek_solver
+        self.system.ekcontainer.tau = self.system.time_step
 
     def tearDown(self):
         self.system.actors.clear()
@@ -85,9 +86,6 @@ def test_ek_species(self):
         ek_species = self.make_default_ek_species()
         self.check_ek_species_properties(ek_species)
 
-        ek_solver = espressomd.electrokinetics.EKNone(lattice=self.lattice)
-        self.system.ekcontainer.tau = self.system.time_step
-        self.system.ekcontainer.solver = ek_solver
         self.assertAlmostEqual(
             self.system.ekcontainer.tau,
             self.system.time_step,
@@ -228,6 +226,12 @@ def test_ek_solver_exceptions(self):
             self.system.ekcontainer.clear()
             self.system.ekcontainer.add(incompatible_ek_species)
             self.system.ekcontainer.solver = ek_solver
+        with self.assertRaisesRegex(ValueError, "Parameter 'tau' must be > 0"):
+            self.system.ekcontainer.tau = 0.
+        self.assertAlmostEqual(
+            self.system.ekcontainer.tau,
+            self.system.time_step,
+            delta=self.atol)
 
     def test_ek_reactants(self):
         ek_species = self.make_default_ek_species()