diff --git a/appveyor.yml b/appveyor.yml
index 02b4461..9e766c5 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -13,10 +13,7 @@ environment:
     - PYTHON: "C:\\Python27-x64"
     - PYTHON: "C:\\Python34-x64"
       DISTUTILS_USE_SDK: "1"
-
-    # Python35-x64 test fails with MemoryError
-    # TODO: investigate it
-    #- PYTHON: "C:\\Python35-x64"
+    - PYTHON: "C:\\Python35-x64"
 
 install:
   # We need wheel installed to build wheels
diff --git a/msgpack/unpack.h b/msgpack/unpack.h
index 92f4f11..da2cfb6 100644
--- a/msgpack/unpack.h
+++ b/msgpack/unpack.h
@@ -265,9 +265,9 @@ static inline int unpack_callback_ext(unpack_user* u, const char* base, const ch
     }
     // length also includes the typecode, so the actual data is length-1
 #if PY_MAJOR_VERSION == 2
-    py = PyObject_CallFunction(u->ext_hook, "(is#)", typecode, pos, length-1);
+    py = PyObject_CallFunction(u->ext_hook, "(is#)", (int)typecode, pos, (Py_ssize_t)length-1);
 #else
-    py = PyObject_CallFunction(u->ext_hook, "(iy#)", typecode, pos, length-1);
+    py = PyObject_CallFunction(u->ext_hook, "(iy#)", (int)typecode, pos, (Py_ssize_t)length-1);
 #endif
     if (!py)
         return -1;
diff --git a/setup.py b/setup.py
index d62c8f2..5f0f08c 100755
--- a/setup.py
+++ b/setup.py
@@ -21,7 +21,7 @@ except ImportError:
 
 def cythonize(src):
     sys.stderr.write("cythonize: %r\n" % (src,))
-    cython_compiler.compile([src], cplus=True, emit_linenums=True)
+    cython_compiler.compile([src], cplus=True)
 
 def ensure_source(src):
     pyx = os.path.splitext(src)[0] + '.pyx'