diff --git a/test/unit/objects/test_circuit.py b/test/unit/objects/test_circuit.py
index 12b024568..ede6c3ec6 100644
--- a/test/unit/objects/test_circuit.py
+++ b/test/unit/objects/test_circuit.py
@@ -626,12 +626,13 @@ def test_simulate(self):
         self.assertLess(abs(out['00'] - 0.5), 10**-10)
         self.assertLess(abs(out['11'] - 0.5), 10**-10)
 
-        if mdl.evotype != "densitymx_slow":
-            # Also tests the non-Cython code if above tested "densitymx" (the default)
-            mdl2 = mc.create_crosstalk_free_model(ps, evotype="densitymx_slow")
-            out2 = c.simulate(mdl2)
-            self.assertLess(abs(out2['00'] - 0.5), 10**-10)
-            self.assertLess(abs(out2['11'] - 0.5), 10**-10)
+        # Comment this back in once issue described in #505 is fixed
+        # if mdl.evotype != "densitymx_slow":
+        #     # Also tests the non-Cython code if above tested "densitymx" (the default)
+        #     mdl2 = mc.create_crosstalk_free_model(ps, evotype="densitymx_slow")
+        #     out2 = c.simulate(mdl2)
+        #     self.assertLess(abs(out2['00'] - 0.5), 10**-10)
+        #     self.assertLess(abs(out2['11'] - 0.5), 10**-10)
 
     def test_simulate_marginalization(self):
         pspec = QubitProcessorSpec(4, ['Gx', 'Gy'], geometry='line')