Try to work around the strange Python 3 behavior.
diff --git a/OpenSSL/crypto.py b/OpenSSL/crypto.py
index 1312c0a..d62ce84 100644
--- a/OpenSSL/crypto.py
+++ b/OpenSSL/crypto.py
@@ -274,6 +274,12 @@
     """
     _curves = None
 
+    def __ne__(self, other):
+        if isinstance(other, _EllipticCurve):
+            return super(_EllipticCurve, self).__ne__(other)
+        return NotImplemented
+
+
     @classmethod
     def _load_elliptic_curves(cls, lib):
         """