diff --git a/bayesian_filters/kalman/tests/test_enkf.py b/bayesian_filters/kalman/tests/test_enkf.py
index 4bbf078..8f19eaa 100644
--- a/bayesian_filters/kalman/tests/test_enkf.py
+++ b/bayesian_filters/kalman/tests/test_enkf.py
@@ -72,7 +72,6 @@ def fx(x, dt):
         plt.plot(results + ps, c="k", linestyle="--")
         plt.legend(loc="best")
         # print(ps)
-    return f
 
 
 def test_circle():
diff --git a/bayesian_filters/kalman/tests/test_mmae.py b/bayesian_filters/kalman/tests/test_mmae.py
index 0b07ab0..ff48194 100644
--- a/bayesian_filters/kalman/tests/test_mmae.py
+++ b/bayesian_filters/kalman/tests/test_mmae.py
@@ -183,8 +183,6 @@ def test_MMAE2():
         plt.plot(xs)
         plt.plot(pos[:, 0])
 
-    return bank
-
 
 if __name__ == "__main__":
     DO_PLOT = True
diff --git a/bayesian_filters/kalman/tests/test_ukf.py b/bayesian_filters/kalman/tests/test_ukf.py
index 36cd4c9..bb0d62c 100644
--- a/bayesian_filters/kalman/tests/test_ukf.py
+++ b/bayesian_filters/kalman/tests/test_ukf.py
@@ -959,7 +959,6 @@ def o_func(x):
 
     assert np.allclose(dx, 0, atol=1e-7)
     assert np.allclose(dxx, 0, atol=1e-6)
-    return ukf
 
 
 def _test_log_likelihood():