diff -r 1c6cf4010df3 Lib/_collections_abc.py
--- a/Lib/_collections_abc.py	Thu May 05 11:14:06 2016 +0300
+++ b/Lib/_collections_abc.py	Thu May 05 18:28:34 2016 +0800
@@ -860,7 +860,8 @@
         i = start
         while stop is None or i < stop:
             try:
-                if self[i] == value:
+                v = self[i]
+                if v is value or v == value:
                     return i
             except IndexError:
                 break
@@ -869,7 +870,7 @@
 
     def count(self, value):
         'S.count(value) -> integer -- return number of occurrences of value'
-        return sum(1 for v in self if v == value)
+        return sum(1 for v in self if v is value or v == value)
 
 Sequence.register(tuple)
 Sequence.register(str)
diff -r 1c6cf4010df3 Lib/test/test_collections.py
--- a/Lib/test/test_collections.py	Thu May 05 11:14:06 2016 +0300
+++ b/Lib/test/test_collections.py	Thu May 05 18:28:34 2016 +0800
@@ -1082,17 +1082,22 @@
         class CustomSequence(list):
             def __contains__(self, value):
                 return Sequence.__contains__(self, value)
+            def index(self, value, start=0, stop=None):
+                return Sequence.index(self, value, start, stop)
+            def count(self, value):
+                return Sequence.count(self, value)
 
         nan = float('nan')
         obj = CustomEqualObject()
-        containers = [
-            CustomSequence([nan, obj]),
-            ItemsView({1: nan, 2: obj}),
-            ValuesView({1: nan, 2: obj})
-        ]
+        seq = CustomSequence([nan, obj, nan])
+        containers = [seq, ItemsView({1: nan, 2: obj}), ValuesView({1: nan, 2: obj})]
         for container in containers:
             for elem in container:
                 self.assertIn(elem, container)
+        self.assertEqual(seq.index(nan), 0)
+        self.assertEqual(seq.index(obj), 1)
+        self.assertEqual(seq.count(nan), 2)
+        self.assertEqual(seq.count(obj), 1)
 
     def assertSameSet(self, s1, s2):
         # coerce both to a real set then check equality