diff --git a/include/mcl/op.hpp b/include/mcl/op.hpp
index 8c973a2..83c62a3 100644
--- a/include/mcl/op.hpp
+++ b/include/mcl/op.hpp
@@ -26,7 +26,7 @@
 
 namespace mcl {
 
-static const int version = 0x137; /* 0xABC = A.BC */
+static const int version = 0x138; /* 0xABC = A.BC */
 
 /*
 	specifies available string format mode for X::setIoMode()