diff --git a/pyerrors/obs.py b/pyerrors/obs.py
index 6724e346..e19cc617 100644
--- a/pyerrors/obs.py
+++ b/pyerrors/obs.py
@@ -795,9 +795,6 @@ class Obs:
     def arctanh(self):
         return derived_observable(lambda x: anp.arctanh(x[0]), [self])
 
-    def sinc(self):
-        return derived_observable(lambda x: anp.sinc(x[0]), [self])
-
 
 class CObs:
     """Class for a complex valued observable."""
diff --git a/tests/obs_test.py b/tests/obs_test.py
index 9aeaf11d..a5e72ec9 100644
--- a/tests/obs_test.py
+++ b/tests/obs_test.py
@@ -57,6 +57,7 @@ def test_dump():
     value = np.random.normal(5, 10)
     dvalue = np.abs(np.random.normal(0, 1))
     test_obs = pe.pseudo_Obs(value, dvalue, 't')
+    test_obs.dump('test_dump', path=".")
     test_obs.dump('test_dump')
     new_obs = pe.load_object('test_dump.p')
     os.remove('test_dump.p')
@@ -105,6 +106,12 @@ def test_function_overloading():
     assert np.sqrt(b ** 2) == b
     assert np.sqrt(b) ** 2 == b
 
+    np.arcsin(1 / b)
+    np.arccos(1 / b)
+    np.arctan(1 / b)
+    np.arctanh(1 / b)
+    np.sinc(1 / b)
+
 
 def test_overloading_vectorization():
     a = np.random.randint(1, 100, 10)