diff --git a/Lib/inspect.py b/Lib/inspect.py
index 3317f58f475..e9c2dbd5c88 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -505,13 +505,16 @@ def unwrap(func, *, stop=None):
         def _is_wrapper(f):
             return hasattr(f, '__wrapped__') and not stop(f)
     f = func  # remember the original func for error reporting
-    memo = {id(f)} # Memoise by id to tolerate non-hashable objects
+    # Memoise by id to tolerate non-hashable objects, but store objects to
+    # ensure they aren't destroyed, which would allow their IDs to be reused.
+    memo = {id(f): f}
+    recursion_limit = sys.getrecursionlimit()
     while _is_wrapper(func):
         func = func.__wrapped__
         id_func = id(func)
-        if id_func in memo:
+        if (id_func in memo) or (len(memo) >= recursion_limit):
             raise ValueError('wrapper loop when unwrapping {!r}'.format(f))
-        memo.add(id_func)
+        memo[id_func] = func
     return func
 
 # -------------------------------------------------- source code extraction
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index facf040d3cd..b194b27aba3 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -3557,6 +3557,19 @@ class TestSignatureDefinitions(unittest.TestCase):
                 self.assertIsNone(obj.__text_signature__)
 
 
+class NTimesUnwrappable:
+    def __init__(self, n):
+        self.n = n
+        self._next = None
+
+    @property
+    def __wrapped__(self):
+        if self.n <= 0:
+            raise Exception("Unwrapped too many times")
+        if self._next is None:
+            self._next = NTimesUnwrappable(self.n - 1)
+        return self._next
+
 class TestUnwrap(unittest.TestCase):
 
     def test_unwrap_one(self):
@@ -3612,6 +3625,11 @@ class TestUnwrap(unittest.TestCase):
             __wrapped__ = func
         self.assertIsNone(inspect.unwrap(C()))
 
+    def test_recursion_limit(self):
+        obj = NTimesUnwrappable(sys.getrecursionlimit() + 1)
+        with self.assertRaisesRegex(ValueError, 'wrapper loop'):
+            inspect.unwrap(obj)
+
 class TestMain(unittest.TestCase):
     def test_only_source(self):
         module = importlib.import_module('unittest')
diff --git a/Misc/NEWS.d/next/Library/2017-09-27-08-11-38.bpo-25532.ey4Yez.rst b/Misc/NEWS.d/next/Library/2017-09-27-08-11-38.bpo-25532.ey4Yez.rst
new file mode 100644
index 00000000000..8146dcdc6d5
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2017-09-27-08-11-38.bpo-25532.ey4Yez.rst
@@ -0,0 +1,3 @@
+inspect.unwrap() will now only try to unwrap an object
+sys.getrecursionlimit() times, to protect against objects which create a new
+object on every attribute access.