diff --git a/smt/applications/tests/test_ego.py b/smt/applications/tests/test_ego.py
index d34133d39..d14fd9bd8 100644
--- a/smt/applications/tests/test_ego.py
+++ b/smt/applications/tests/test_ego.py
@@ -1120,7 +1120,7 @@ def f_obj(X):
             LHS, design_space, criterion="ese", random_state=random_state
         )
         Xt = sampling(n_doe)
-        if ds.HAS_CONFIG_SPACE:  # results differs wrt config_space impl
+        if ds.HAS_DESIGN_SPACE_EXT:  # results differs wrt config_space impl
             self.assertAlmostEqual(np.sum(Xt), 24.811925491708156, delta=1e-4)
         else:
             self.assertAlmostEqual(np.sum(Xt), 28.568852027679586, delta=1e-4)
@@ -1155,7 +1155,7 @@ def f_obj(X):
             n_start=25,
         )
         x_opt, y_opt, dnk, x_data, y_data = ego.optimize(fun=f_obj)
-        if ds.HAS_CONFIG_SPACE:  # results differs wrt config_space impl
+        if ds.HAS_DESIGN_SPACE_EXT:  # results differs wrt config_space impl
             self.assertAlmostEqual(np.sum(y_data), 8.846225704750577, delta=1e-4)
             self.assertAlmostEqual(np.sum(x_data), 41.811925504901374, delta=1e-4)
         else:
diff --git a/smt/applications/tests/test_mixed_integer.py b/smt/applications/tests/test_mixed_integer.py
index c368b413d..224a6664a 100644
--- a/smt/applications/tests/test_mixed_integer.py
+++ b/smt/applications/tests/test_mixed_integer.py
@@ -17,9 +17,8 @@
 except ImportError:
     NO_MATPLOTLIB = True
 
-import smt.design_space as ds
 from smt.design_space import (
-    HAS_CONFIG_SPACE,
+    HAS_DESIGN_SPACE_EXT,
     DesignSpace,
     CategoricalVariable,
     FloatVariable,
@@ -464,7 +463,7 @@ def test_examples(self):
         self.run_mixed_gower_example()
         self.run_mixed_homo_gaussian_example()
         self.run_mixed_homo_hyp_example()
-        if ds.HAS_CONFIG_SPACE:
+        if HAS_DESIGN_SPACE_EXT:
             self.run_mixed_cs_example()
             self.run_hierarchical_design_space_example()  # works only with config space impl
 
@@ -918,7 +917,7 @@ def run_hierarchical_design_space_example(self):
         self._sm = sm  # to be ignored: just used for automated test
 
     @unittest.skipIf(
-        not HAS_CONFIG_SPACE, "Hierarchy ConfigSpace dependency not installed"
+        not HAS_DESIGN_SPACE_EXT, "Hierarchy ConfigSpace dependency not installed"
     )
     def test_hierarchical_design_space_example(self):
         self.run_hierarchical_design_space_example()
@@ -951,7 +950,7 @@ def test_hierarchical_design_space_example(self):
         )
 
     @unittest.skipIf(
-        not HAS_CONFIG_SPACE, "Hierarchy ConfigSpace dependency not installed"
+        not HAS_DESIGN_SPACE_EXT, "Hierarchy ConfigSpace dependency not installed"
     )
     def test_hierarchical_design_space_example_all_categorical_decreed(self):
         ds = DesignSpace(
diff --git a/smt/design_space/tests/test_design_space.py b/smt/design_space/tests/test_design_space.py
index a977a12c2..b6ffab49e 100644
--- a/smt/design_space/tests/test_design_space.py
+++ b/smt/design_space/tests/test_design_space.py
@@ -2,7 +2,6 @@
 Author: Jasper Bussemaker <jasper.bussemaker@dlr.de>
 """
 
-import contextlib
 import itertools
 import unittest
 
@@ -11,7 +10,6 @@
 from smt.sampling_methods import LHS
 
 
-import smt.design_space.design_space as ds
 from smt.design_space.design_space import (
     BaseDesignSpace,
     CategoricalVariable,
@@ -22,16 +20,6 @@
 )
 
 
-@contextlib.contextmanager
-def simulate_no_config_space(do_simulate=True):
-    if ds.HAS_CONFIG_SPACE and do_simulate:
-        ds.HAS_CONFIG_SPACE = False
-        yield
-        ds.HAS_CONFIG_SPACE = True
-    else:
-        yield
-
-
 class Test(unittest.TestCase):
     def test_design_variables(self):
         with self.assertRaises(ValueError):
@@ -193,8 +181,6 @@ def test_base_design_space(self):
 
     def test_create_design_space(self):
         DesignSpace([FloatVariable(0, 1)])
-        with simulate_no_config_space():
-            DesignSpace([FloatVariable(0, 1)])
 
     def test_design_space(self):
         ds = DesignSpace(
@@ -421,22 +407,20 @@ def test_design_space_hierarchical(self):
         assert len(seen_is_acting) == 2
 
     def test_check_conditionally_acting_2(self):
-        for simulate_no_cs in [True, False]:
-            with simulate_no_config_space(simulate_no_cs):
-                ds = DesignSpace(
-                    [
-                        CategoricalVariable(["A", "B", "C"]),  # x0
-                        CategoricalVariable(["E", "F"]),  # x1
-                        IntegerVariable(0, 1),  # x2
-                        FloatVariable(0, 1),  # x3
-                    ],
-                    random_state=42,
-                )
-                ds.declare_decreed_var(
-                    decreed_var=0, meta_var=1, meta_value="E"
-                )  # Activate x3 if x0 == A
+        ds = DesignSpace(
+            [
+                CategoricalVariable(["A", "B", "C"]),  # x0
+                CategoricalVariable(["E", "F"]),  # x1
+                IntegerVariable(0, 1),  # x2
+                FloatVariable(0, 1),  # x3
+            ],
+            random_state=42,
+        )
+        ds.declare_decreed_var(
+            decreed_var=0, meta_var=1, meta_value="E"
+        )  # Activate x3 if x0 == A
 
-                ds.sample_valid_x(10, random_state=42)
+        ds.sample_valid_x(10, random_state=42)
 
 
 if __name__ == "__main__":