diff --git a/src/emcal/plotting.py b/src/emcal/plotting.py
index 5965d95..d04e803 100644
--- a/src/emcal/plotting.py
+++ b/src/emcal/plotting.py
@@ -562,7 +562,7 @@ def plot_gp_fit(
                     z,
                     levels=cbar_ticks,
                     # tick_positions=nticks,
-                    cmap=plt.cm.get_cmap(self.cmap),
+                    cmap=plt.colormaps[self.cmap],
                     norm=norm,
                 )
 
diff --git a/tests/unit/test_acquisition.py b/tests/unit/test_acquisition.py
index 4958d9d..0f696d5 100644
--- a/tests/unit/test_acquisition.py
+++ b/tests/unit/test_acquisition.py
@@ -134,6 +134,7 @@ def test_ei_log_emulator_is_zero_when_variance_non_positive():
 # --- __calc_ei_sparse (method 5, sparse-grid integrated EI / 2C) -------------------------
 
 def test_ei_sparse_is_deterministic_and_nonnegative():
+    pytest.importorskip("Tasmanian")
     best_error_x, ep_curr, var = 2.0, 1.5, 0.25
     method = GPBOMethod(MethodName.SPARSE_GRID)
 
@@ -190,6 +191,7 @@ def test_ei_mc_is_zero_when_variance_negative():
 
 
 def test_ei_sparse_ldl_fallback_for_non_positive_definite_covariance():
+    pytest.importorskip("Tasmanian")
     # __calc_ei_sparse diagonalizes self.gp_covar with Cholesky, falling back to LDL when
     # that fails; a non-PD covariance (eigenvalues 3, -1) forces the except branch.
     method = GPBOMethod(MethodName.SPARSE_GRID)
diff --git a/tests/unit/test_calibration_problem.py b/tests/unit/test_calibration_problem.py
index ca90042..a6322b2 100644
--- a/tests/unit/test_calibration_problem.py
+++ b/tests/unit/test_calibration_problem.py
@@ -67,6 +67,8 @@ def test_bad_bound_order():
 
 @pytest.mark.parametrize("cs", BUILT_INS)
 def test_get_case_study_returns_valid_problem(cs):
+    if cs in (2, 3):
+        pytest.importorskip("pyomo")
     p = get_case_study(cs)
     assert isinstance(p, CalibrationProblem)
     assert len(p.param_names) == len(p.param_bounds)