diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -21,6 +21,7 @@ This document follows the conventions laid out in [Keep a CHANGELOG][].
 
 ### Fixed
 
+-   Fixed interop methods with Py_ssize_t. NetCoreApp 2.0 is more sensitive than net40 and requires this fix. 
 -   Fixed Visual Studio 2017 compat (#434) for setup.py
 -   Fixed crash on exit of the Python interpreter if a python class
     derived from a .NET class has a `__namespace__` or `__assembly__`

diff --git a/src/embed_tests/TestPySequence.cs b/src/embed_tests/TestPySequence.cs
@@ -69,10 +69,8 @@ public void TestRepeat()
             PyObject actual = t1.Repeat(3);
             Assert.AreEqual("FooFooFoo", actual.ToString());
 
-            // On 32 bit system this argument should be int, but on the 64 bit system this should be long value.
-            // This works on the Framework 4.0 accidentally, it should produce out of memory!
-            // actual = t1.Repeat(-3);
-            // Assert.AreEqual("", actual.ToString());
+            actual = t1.Repeat(-3);
+            Assert.AreEqual("", actual.ToString());
         }
 
         [Test]

diff --git a/src/runtime/exceptions.cs b/src/runtime/exceptions.cs
@@ -276,7 +276,7 @@ public static void SetError(Exception e)
         /// </remarks>
         public static bool ErrorOccurred()
         {
-            return Runtime.PyErr_Occurred() != 0;
+            return Runtime.PyErr_Occurred() != IntPtr.Zero;
         }
 
         /// <summary>