diff --git a/include/mcl/op.hpp b/include/mcl/op.hpp
index e43a41a9..c5ab7b44 100644
--- a/include/mcl/op.hpp
+++ b/include/mcl/op.hpp
@@ -29,7 +29,7 @@
 
 namespace mcl {
 
-static const int version = 0x187; /* 0xABC = A.BC */
+static const int version = 0x188; /* 0xABC = A.BC */
 
 /*
 	specifies available string format mode for X::setIoMode()