diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index e14df9ea089..228bc17b23c 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -391,6 +391,26 @@ class List(list): pass
         lyst = List()
         self.assertEqual(bool(weakref.proxy(lyst)), bool(lyst))
 
+    def test_proxy_iter(self):
+        # Test fails with a debug build of the interpreter
+        # (see bpo-38395).
+
+        obj = None
+
+        class MyObj:
+            def __iter__(self):
+                nonlocal obj
+                del obj
+                return NotImplemented
+
+        obj = MyObj()
+        p = weakref.proxy(obj)
+        with self.assertRaises(TypeError):
+            # "blech" in p calls MyObj.__iter__ through the proxy,
+            # without keeping a reference to the real object, so it
+            # can be killed in the middle of the call
+            "blech" in p
+
     def test_getweakrefcount(self):
         o = C()
         ref1 = weakref.ref(o)
diff --git a/Misc/NEWS.d/next/C API/2019-10-08-01-23-24.bpo-38395.MJ6Ey9.rst b/Misc/NEWS.d/next/C API/2019-10-08-01-23-24.bpo-38395.MJ6Ey9.rst
new file mode 100644
index 00000000000..4bc30600ca7
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2019-10-08-01-23-24.bpo-38395.MJ6Ey9.rst	
@@ -0,0 +1,3 @@
+Fix a crash in :class:`weakref.proxy` objects due to incorrect lifetime
+management when calling some associated methods that may delete the last
+reference to object being referenced by the proxy. Patch by Pablo Galindo.
diff --git a/Objects/weakrefobject.c b/Objects/weakrefobject.c
index daee476444a..bf79e0c7ecb 100644
--- a/Objects/weakrefobject.c
+++ b/Objects/weakrefobject.c
@@ -145,11 +145,14 @@ weakref_hash(PyWeakReference *self)
 {
     if (self->hash != -1)
         return self->hash;
-    if (PyWeakref_GET_OBJECT(self) == Py_None) {
+    PyObject* obj = PyWeakref_GET_OBJECT(self);
+    if (obj == Py_None) {
         PyErr_SetString(PyExc_TypeError, "weak object has gone away");
         return -1;
     }
-    self->hash = PyObject_Hash(PyWeakref_GET_OBJECT(self));
+    Py_INCREF(obj);
+    self->hash = PyObject_Hash(obj);
+    Py_DECREF(obj);
     return self->hash;
 }
 
@@ -159,11 +162,15 @@ weakref_repr(PyWeakReference *self)
 {
     PyObject *name, *repr;
     _Py_IDENTIFIER(__name__);
+    PyObject* obj = PyWeakref_GET_OBJECT(self);
 
-    if (PyWeakref_GET_OBJECT(self) == Py_None)
+    if (obj == Py_None) {
         return PyUnicode_FromFormat("<weakref at %p; dead>", self);
+    }
 
-    if (_PyObject_LookupAttrId(PyWeakref_GET_OBJECT(self), &PyId___name__, &name) < 0) {
+    Py_INCREF(obj);
+    if (_PyObject_LookupAttrId(obj, &PyId___name__, &name) < 0) {
+        Py_DECREF(obj);
         return NULL;
     }
     if (name == NULL || !PyUnicode_Check(name)) {
@@ -171,16 +178,17 @@ weakref_repr(PyWeakReference *self)
             "<weakref at %p; to '%s' at %p>",
             self,
             Py_TYPE(PyWeakref_GET_OBJECT(self))->tp_name,
-            PyWeakref_GET_OBJECT(self));
+            obj);
     }
     else {
         repr = PyUnicode_FromFormat(
             "<weakref at %p; to '%s' at %p (%U)>",
             self,
             Py_TYPE(PyWeakref_GET_OBJECT(self))->tp_name,
-            PyWeakref_GET_OBJECT(self),
+            obj,
             name);
     }
+    Py_DECREF(obj);
     Py_XDECREF(name);
     return repr;
 }
@@ -207,8 +215,14 @@ weakref_richcompare(PyWeakReference* self, PyWeakReference* other, int op)
         else
             Py_RETURN_FALSE;
     }
-    return PyObject_RichCompare(PyWeakref_GET_OBJECT(self),
-                                PyWeakref_GET_OBJECT(other), op);
+    PyObject* obj = PyWeakref_GET_OBJECT(self);
+    PyObject* other_obj = PyWeakref_GET_OBJECT(other);
+    Py_INCREF(obj);
+    Py_INCREF(other_obj);
+    PyObject* res = PyObject_RichCompare(obj, other_obj, op);
+    Py_DECREF(obj);
+    Py_DECREF(other_obj);
+    return res;
 }
 
 /* Given the head of an object's list of weak references, extract the
@@ -415,18 +429,14 @@ proxy_checkref(PyWeakReference *proxy)
             o = PyWeakref_GET_OBJECT(o); \
         }
 
-#define UNWRAP_I(o) \
-        if (PyWeakref_CheckProxy(o)) { \
-            if (!proxy_checkref((PyWeakReference *)o)) \
-                return -1; \
-            o = PyWeakref_GET_OBJECT(o); \
-        }
-
 #define WRAP_UNARY(method, generic) \
     static PyObject * \
     method(PyObject *proxy) { \
         UNWRAP(proxy); \
-        return generic(proxy); \
+        Py_INCREF(proxy); \
+        PyObject* res = generic(proxy); \
+        Py_DECREF(proxy); \
+        return res; \
     }
 
 #define WRAP_BINARY(method, generic) \
@@ -434,7 +444,12 @@ proxy_checkref(PyWeakReference *proxy)
     method(PyObject *x, PyObject *y) { \
         UNWRAP(x); \
         UNWRAP(y); \
-        return generic(x, y); \
+        Py_INCREF(x); \
+        Py_INCREF(y); \
+        PyObject* res = generic(x, y); \
+        Py_DECREF(x); \
+        Py_DECREF(y); \
+        return res; \
     }
 
 /* Note that the third arg needs to be checked for NULL since the tp_call
@@ -447,7 +462,14 @@ proxy_checkref(PyWeakReference *proxy)
         UNWRAP(v); \
         if (w != NULL) \
             UNWRAP(w); \
-        return generic(proxy, v, w); \
+        Py_INCREF(proxy); \
+        Py_INCREF(v); \
+        Py_XINCREF(w); \
+        PyObject* res = generic(proxy, v, w); \
+        Py_DECREF(proxy); \
+        Py_DECREF(v); \
+        Py_XDECREF(w); \
+        return res; \
     }
 
 #define WRAP_METHOD(method, special) \
@@ -455,7 +477,10 @@ proxy_checkref(PyWeakReference *proxy)
     method(PyObject *proxy, PyObject *Py_UNUSED(ignored)) { \
             _Py_IDENTIFIER(special); \
             UNWRAP(proxy); \
-                return _PyObject_CallMethodIdNoArgs(proxy, &PyId_##special); \
+            Py_INCREF(proxy); \
+            PyObject* res = _PyObject_CallMethodIdNoArgs(proxy, &PyId_##special); \
+            Py_DECREF(proxy); \
+            return res; \
         }
 
 
@@ -481,7 +506,11 @@ proxy_setattr(PyWeakReference *proxy, PyObject *name, PyObject *value)
 {
     if (!proxy_checkref(proxy))
         return -1;
-    return PyObject_SetAttr(PyWeakref_GET_OBJECT(proxy), name, value);
+    PyObject *obj = PyWeakref_GET_OBJECT(proxy);
+    Py_INCREF(obj);
+    int res = PyObject_SetAttr(obj, name, value);
+    Py_DECREF(obj);
+    return res;
 }
 
 static PyObject *
@@ -532,9 +561,13 @@ static int
 proxy_bool(PyWeakReference *proxy)
 {
     PyObject *o = PyWeakref_GET_OBJECT(proxy);
-    if (!proxy_checkref(proxy))
+    if (!proxy_checkref(proxy)) {
         return -1;
-    return PyObject_IsTrue(o);
+    }
+    Py_INCREF(o);
+    int res = PyObject_IsTrue(o);
+    Py_DECREF(o);
+    return res;
 }
 
 static void
@@ -553,9 +586,13 @@ proxy_contains(PyWeakReference *proxy, PyObject *value)
 {
     if (!proxy_checkref(proxy))
         return -1;
-    return PySequence_Contains(PyWeakref_GET_OBJECT(proxy), value);
-}
 
+    PyObject *obj = PyWeakref_GET_OBJECT(proxy);
+    Py_INCREF(obj);
+    int res = PySequence_Contains(obj, value);
+    Py_DECREF(obj);
+    return res;
+}
 
 /* mapping slots */
 
@@ -564,7 +601,12 @@ proxy_length(PyWeakReference *proxy)
 {
     if (!proxy_checkref(proxy))
         return -1;
-    return PyObject_Length(PyWeakref_GET_OBJECT(proxy));
+
+    PyObject *obj = PyWeakref_GET_OBJECT(proxy);
+    Py_INCREF(obj);
+    Py_ssize_t res = PyObject_Length(obj);
+    Py_DECREF(obj);
+    return res;
 }
 
 WRAP_BINARY(proxy_getitem, PyObject_GetItem)
@@ -575,10 +617,16 @@ proxy_setitem(PyWeakReference *proxy, PyObject *key, PyObject *value)
     if (!proxy_checkref(proxy))
         return -1;
 
-    if (value == NULL)
-        return PyObject_DelItem(PyWeakref_GET_OBJECT(proxy), key);
-    else
-        return PyObject_SetItem(PyWeakref_GET_OBJECT(proxy), key, value);
+    PyObject *obj = PyWeakref_GET_OBJECT(proxy);
+    Py_INCREF(obj);
+    int res;
+    if (value == NULL) {
+        res = PyObject_DelItem(obj, key);
+    } else {
+        res = PyObject_SetItem(obj, key, value);
+    }
+    Py_DECREF(obj);
+    return res;
 }
 
 /* iterator slots */
@@ -588,7 +636,11 @@ proxy_iter(PyWeakReference *proxy)
 {
     if (!proxy_checkref(proxy))
         return NULL;
-    return PyObject_GetIter(PyWeakref_GET_OBJECT(proxy));
+    PyObject *obj = PyWeakref_GET_OBJECT(proxy);
+    Py_INCREF(obj);
+    PyObject* res = PyObject_GetIter(obj);
+    Py_DECREF(obj);
+    return res;
 }
 
 static PyObject *
@@ -596,7 +648,12 @@ proxy_iternext(PyWeakReference *proxy)
 {
     if (!proxy_checkref(proxy))
         return NULL;
-    return PyIter_Next(PyWeakref_GET_OBJECT(proxy));
+
+    PyObject *obj = PyWeakref_GET_OBJECT(proxy);
+    Py_INCREF(obj);
+    PyObject* res = PyIter_Next(obj);
+    Py_DECREF(obj);
+    return res;
 }