diff --git a/src/Serialization.h b/src/Serialization.h
index cccfc54..91a8fa4 100644
--- a/src/Serialization.h
+++ b/src/Serialization.h
@@ -40,6 +40,11 @@
 #include <assert.h>
 #include <functional>

+#ifdef _MSC_VER
+#include <BaseTsd.h>
+using ssize_t = SSIZE_T;
+#endif
+
 #ifndef __has_extension
 # define __has_extension(x) 0
 #endif