diff --git a/.travis.yml b/.travis.yml
index 8b2423d..6b1f33c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,14 +1,17 @@
 language: python
+python:
+  - 3.5
+
 env:
   - TOXENV=py26
   - TOXENV=py27
-  - TOXENV=py32
   - TOXENV=py33
   - TOXENV=py34
+  - TOXENV=py35
   - TOXENV=rhel6
 
 install:
-  - pip install tox
+  - pip install -U tox
 
 script:
   - tox
diff --git a/mixbox/signals.py b/mixbox/signals.py
index 67a79b5..3b81a7b 100644
--- a/mixbox/signals.py
+++ b/mixbox/signals.py
@@ -18,7 +18,7 @@
 try:
     from weakref import WeakMethod
 except ImportError:
-    from weakrefmethod import WeakMethod
+    from .vendor.weakrefmethod import WeakMethod
 
 
 # Module-level logger
diff --git a/mixbox/vendor/weakrefmethod.py b/mixbox/vendor/weakrefmethod.py
new file mode 100644
index 0000000..6ccaa3f
--- /dev/null
+++ b/mixbox/vendor/weakrefmethod.py
@@ -0,0 +1,56 @@
+import weakref
+
+"""NOTE: Remove this class in favor of using weakrefmethod as a dependency
+once the PyPI version of the weakrefmethod module has the changes from
+https://github.com/twang817/weakrefmethod/pull/4
+"""
+
+__all__ = ['WeakMethod']
+
+class WeakMethod(weakref.ref):
+    """
+    A custom 'weakref.ref' subclass which simulates a weak reference to
+    a bound method, working around the lifetime problem of bound methods
+    """
+
+    __slots__ = '_func_ref', '_meth_type', '_alive', '__weakref__'
+
+    def __new__(cls, meth, callback=None):
+        try:
+            obj = meth.__self__
+            func = meth.__func__
+        except AttributeError:
+            raise TypeError('argument should be a bound method, not {0}'.format(type(meth)))
+
+        def _cb(arg):
+            # The self-weakref trick is needed to avoid creating a reference cycle.
+            self = self_wr()
+            if self._alive:
+                self._alive = False
+                if callback is not None:
+                    callback(self)
+        self = weakref.ref.__new__(cls, obj, _cb)
+        self._func_ref = weakref.ref(func, _cb)
+        self._meth_type = type(meth)
+        self._alive = True
+        self_wr = weakref.ref(self)
+        return self
+
+    def __call__(self):
+        obj = super(WeakMethod, self).__call__()
+        func = self._func_ref()
+        if obj is None or func is None:
+            return None
+        return self._meth_type(func, obj)
+
+    def __eq__(self, other):
+        if isinstance(other, WeakMethod):
+            if not self._alive or not other._alive:
+                return self is other
+            return weakref.ref.__eq__(self, other) and self._func_ref == other._func_ref
+        return False
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    __hash__ = weakref.ref.__hash__
diff --git a/setup.py b/setup.py
index 5533415..1ae3c3d 100644
--- a/setup.py
+++ b/setup.py
@@ -32,13 +32,6 @@ def get_version():
     install_requires.append('weakrefset')
 
 
-# WeakMethod was introduced in Python 3.4
-try:
-    from weakref import WeakMethod
-except ImportError:
-    install_requires.append('weakrefmethod')
-
-
 extras_require = {
     'docs': [
         'Sphinx==1.3.1',
diff --git a/tox.ini b/tox.ini
index 2454215..b2fb670 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py26, py27, py32, py33, py34, rhel6
+envlist = py26, py27, py33, py34, py35, rhel6
 
 [testenv]
 commands =