ifdef WIN32 -> _WIN32
diff --git a/include/pybind11/pytypes.h b/include/pybind11/pytypes.h
index 98c6f8e..7d7cd9f 100644
--- a/include/pybind11/pytypes.h
+++ b/include/pybind11/pytypes.h
@@ -272,7 +272,7 @@
PYBIND11_OBJECT_DEFAULT(int_, object, PyLong_Check)
int_(int value) : object(PyLong_FromLong((long) value), false) { }
int_(size_t value) : object(PyLong_FromSize_t(value), false) { }
-#if !(defined(WIN32) || defined(__i386__)) || defined(_WIN64)
+#if !(defined(_WIN32) || defined(__i386__)) || defined(_WIN64)
int_(ssize_t value) : object(PyLong_FromSsize_t(value), false) { }
#endif
operator int() const { return (int) PyLong_AsLong(m_ptr); }