diff --git a/include/boost/python/detail/caller.hpp b/include/boost/python/detail/caller.hpp
index e479bf427..39cc3603f 100644
--- a/include/boost/python/detail/caller.hpp
+++ b/include/boost/python/detail/caller.hpp
@@ -50,7 +50,7 @@ inline PyObject* get(mpl::int_<N>, PyObject* const& args_)
     return PyTuple_GET_ITEM(args_,N);
 }
 
-inline unsigned arity(PyObject* const& args_)
+inline Py_ssize_t arity(PyObject* const& args_)
 {
     return PyTuple_GET_SIZE(args_);
 }
diff --git a/include/boost/python/list.hpp b/include/boost/python/list.hpp
index 10fd40fda..0d5e2c8fd 100644
--- a/include/boost/python/list.hpp
+++ b/include/boost/python/list.hpp
@@ -73,7 +73,7 @@ class list : public detail::list_base
     }
 
     template <class T>
-    long count(T const& value) const
+    ssize_t count(T const& value) const
     {
         return base::count(object(value));
     }