diff --git a/legacy/evil/src/lib/Evil.h b/legacy/evil/src/lib/Evil.h
index effc2553d0..017ae8fcf9 100644
--- a/legacy/evil/src/lib/Evil.h
+++ b/legacy/evil/src/lib/Evil.h
@@ -97,6 +97,7 @@ typedef unsigned short mode_t;
 typedef unsigned short uint16_t;
 typedef unsigned int uint32_t;
 typedef signed int int32_t;
+typedef __int64 int64_t;
 typedef unsigned __int64 uint64_t;
 
 #endif /* _MSC_VER */