diff --git a/src/gig.h b/src/gig.h
index 173e4f5..b9d117a 100644
--- a/src/gig.h
+++ b/src/gig.h
@@ -44,6 +44,11 @@
 # warning No RTTI available!
 #endif
 
+#ifdef _MSC_VER
+#include <BaseTsd.h>
+using ssize_t = SSIZE_T;
+#endif
+
 #if WORDS_BIGENDIAN
 # define LIST_TYPE_3PRG	0x33707267
 # define LIST_TYPE_3EWL	0x3365776C