diff --git a/Cargo.toml b/Cargo.toml
index 50de39c..078c517 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "k"
-version = "0.17.0"
+version = "0.18.0"
 authors = ["Takashi Ogura <t.ogura@gmail.com>"]
 description = "k is for kinematics"
 license = "Apache-2.0"