diff --git a/testsuite/python/ek_charged_plate.py b/testsuite/python/ek_charged_plate.py
index 4a078336d1e..6b13be4381b 100644
--- a/testsuite/python/ek_charged_plate.py
+++ b/testsuite/python/ek_charged_plate.py
@@ -163,6 +163,12 @@ def test(self):
                 positive_ions[i, j, 10].density = 0.0
                 negative_ions[i, j, 30].density = 0.0
 
+        # Test error when trying to change ekin parameters after initialisation
+        ek._params.update({'agrid': 3,
+                           'T': 0.01})
+        with self.assertRaises(RuntimeError):
+            ek._set_params_in_es_core()
+
 
 if __name__ == "__main__":
     ut.main()