diff --git a/json_inttypes.h b/json_inttypes.h
index e047d4f..a901a8e 100644
--- a/json_inttypes.h
+++ b/json_inttypes.h
@@ -21,4 +21,9 @@
 
 #endif
 
+#if defined(_MSC_VER)
+#include <BaseTsd.h>
+typedef SSIZE_T ssize_t;
+#endif
+
 #endif