diff --git a/randomgen/entropy.pyx b/randomgen/entropy.pyx
index 037f9432e..41e88a3b5 100644
--- a/randomgen/entropy.pyx
+++ b/randomgen/entropy.pyx
@@ -27,13 +27,12 @@ cdef Py_ssize_t compute_numel(size):
     return n
 
 cdef class TestSentinel(object):
-    cdef bint _testing_auto, _testing_system, _testing_fallback
-    def __init__(self, object auto=False, system=False, fallback=False):
+    cdef bint _testing_auto, _testing_fallback
+
+    def __init__(self, object auto=False, fallback=False):
         self._testing_auto = auto
-        self._testing_system = system
         self._testing_fallback = fallback
 
-
     @property
     def testing_auto(self):
         return self._testing_auto
@@ -42,14 +41,6 @@ cdef class TestSentinel(object):
     def testing_auto(self, object value):
         self._testing_auto = value
 
-    @property
-    def testing_system(self):
-        return self._testing_system
-
-    @testing_system.setter
-    def testing_system(self, object value):
-        self._testing_system = value
-
     @property
     def testing_fallback(self):
         return self._testing_fallback