--- a/parser/python_header.h
+++ b/parser/python_header.h
@@ -13,6 +13,7 @@
#include <language/duchain/duchainlock.h>
+#include <sys/types.h> /* define ssize_t with musl libc */
#include "pyport.h"
#ifndef _WIN32
#include "pyconfig.h"