diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py
index aeb6d17..e0ca746 100644
--- a/Lib/test/test_deque.py
+++ b/Lib/test/test_deque.py
@@ -29,8 +29,8 @@
 class TestBasic(unittest.TestCase):
 
     def test_basics(self):
-        d = deque(xrange(100))
-        d.__init__(xrange(100, 200))
+        d = deque(xrange(-5125, -5000))
+        d.__init__(xrange(200))
         for i in xrange(200, 400):
             d.append(i)
         for i in reversed(xrange(-200, 0)):
@@ -451,8 +451,8 @@
 class TestSubclass(unittest.TestCase):
 
     def test_basics(self):
-        d = Deque(xrange(100))
-        d.__init__(xrange(100, 200))
+        d = Deque(xrange(25))
+        d.__init__(xrange(200))
         for i in xrange(200, 400):
             d.append(i)
         for i in reversed(xrange(-200, 0)):
diff --git a/Misc/NEWS b/Misc/NEWS
index 679f1fe..7dae508 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -881,6 +881,10 @@
 Extension Modules
 -----------------
 
+- Bug #1604: collections.deque.__init__(iterable) now clears any prior contents
+  before adding elements from the iterable.  This fix brings the behavior into
+  line with that for list.__init__().
+
 - Added wide char functions to msvcrt module: getwch, getwche, putwch and
   ungetwch. The functions accept or return unicode.
 
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index e5c3218..9efbc27 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -843,6 +843,7 @@
 		}
 	}
 	deque->maxlen = maxlen;
+	deque_clear(deque);
 	if (iterable != NULL) {
 		PyObject *rv = deque_extend(deque, iterable);
 		if (rv == NULL)