diff --git a/examples/irasa_sprint.ipynb b/examples/irasa_sprint.ipynb
index bf11504..0cbb2b0 100644
--- a/examples/irasa_sprint.ipynb
+++ b/examples/irasa_sprint.ipynb
@@ -513,7 +513,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.12.4"
+   "version": "3.1.undefined"
   }
  },
  "nbformat": 4,
diff --git a/tests/conftest.py b/tests/conftest.py
index b6cc310..5eb63c6 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -87,6 +87,35 @@ def ts4sprint(fs, exponent_1, exponent_2):
     yield sim_ts
 
 
+@pytest.fixture(scope='session')
+def ts4sprint_knee(fs, exponent_1, exponent_2):
+    alpha = sim_oscillation(n_seconds=0.5, fs=fs, freq=10)
+    no_alpha = np.zeros(len(alpha))
+    beta = sim_oscillation(n_seconds=0.5, fs=fs, freq=25)
+    no_beta = np.zeros(len(beta))
+
+    knee1 = 20 ** np.abs(exponent_1)
+    knee2 = 20 ** np.abs(exponent_2)
+    exp_1 = sim_knee(n_seconds=2.5, fs=fs, exponent1=0, exponent2=exponent_1, knee=knee1)
+    exp_2 = sim_knee(n_seconds=2.5, fs=fs, exponent1=0, exponent2=exponent_2, knee=knee2)
+
+    # %%
+    alphas = np.concatenate([no_alpha, alpha, no_alpha, alpha, no_alpha])
+    betas = np.concatenate([beta, no_beta, beta, no_beta, beta])
+
+    sim_ts = np.concatenate(
+        [
+            exp_1 + alphas,
+            exp_1 + alphas + betas,
+            exp_1 + betas,
+            exp_2 + alphas,
+            exp_2 + alphas + betas,
+            exp_2 + betas,
+        ]
+    )
+    yield sim_ts
+
+
 @pytest.fixture(scope='session')
 def gen_mne_data_raw():
     data_path = sample.data_path()
diff --git a/tests/test_irasa_knee.py b/tests/test_irasa_knee.py
index d951ca4..e28194a 100644
--- a/tests/test_irasa_knee.py
+++ b/tests/test_irasa_knee.py
@@ -114,9 +114,9 @@ def test_aperiodic_error(load_knee_cmb_signal, fs, exponent, knee, osc_freq):
 @pytest.mark.parametrize('fs', [1000], scope='session')
 @pytest.mark.parametrize('exponent_1', [-0], scope='session')
 @pytest.mark.parametrize('exponent_2', [-2], scope='session')
-def test_aperiodic_error_tf(ts4sprint, fs, exponent, knee, osc_freq):
+def test_aperiodic_error_tf(ts4sprint_knee, fs, exponent_1, exponent_2):
     irasa_out = irasa_sprint(
-        ts4sprint,
+        ts4sprint_knee,
         fs=fs,
         band=(0.1, 50),
         overlap_fraction=0.95,
@@ -125,7 +125,7 @@ def test_aperiodic_error_tf(ts4sprint, fs, exponent, knee, osc_freq):
     )
 
     irasa_out_bad = irasa_sprint(
-        ts4sprint,
+        ts4sprint_knee,
         fs=fs,
         band=(0.1, 50),
         overlap_fraction=0.95,
@@ -133,4 +133,14 @@ def test_aperiodic_error_tf(ts4sprint, fs, exponent, knee, osc_freq):
         hset_info=(1, 8.0, 0.05),
     )
 
-    assert np.mean(irasa_out.get_aperiodic_error()) < np.mean(irasa_out_bad.get_aperiodic_error())
+    kwargs = {
+        'cut_spectrum': (1, 40),
+        'smooth': True,
+        'smoothing_window': 3,
+        'min_peak_height': 0.01,
+        'peak_width_limits': (0.5, 12),
+    }
+
+    assert np.mean(irasa_out.get_aperiodic_error(peak_kwargs=kwargs)) < np.mean(
+        irasa_out_bad.get_aperiodic_error(peak_kwargs=kwargs)
+    )