diff --git a/RELEASE.md b/RELEASE.md
index aea95bca..08ea500a 100644
--- a/RELEASE.md
+++ b/RELEASE.md
@@ -37,15 +37,16 @@ Bump version
 2. Checkout `master` branch.
 3. Make a branch to release, for example by `git neco dev "$VERSION"`
 4. Edit `CHANGELOG.md` for the new version ([example][]).
-5. Commit the change and push it.
+5. Edit `version.go` for the new version.
+6. Commit the changes and push it.
 
     ```console
     $ git commit -a -m "Bump version to $VERSION"
     $ git neco review
     ```
-6. Merge this branch.
-7. Checkout `master` branch.
-8. Add a git tag, then push it.
+7. Merge this branch.
+8. Checkout `master` branch.
+9. Add a git tag, then push it.
 
     ```console
     $ git tag "v$VERSION"
diff --git a/pkg/coil-controller/cmd/root.go b/pkg/coil-controller/cmd/root.go
index 92f41128..20e55b18 100644
--- a/pkg/coil-controller/cmd/root.go
+++ b/pkg/coil-controller/cmd/root.go
@@ -29,8 +29,9 @@ var etcdConfig *etcdutil.Config
 
 // rootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
-	Use:   "coil-controller",
-	Short: "A kubernetes controller for coil",
+	Use:     "coil-controller",
+	Version: coil.Version,
+	Short:   "A kubernetes controller for coil",
 	Long: `coil-controller is a Kubernetes controller to maintain coil resources.
 
 It should be deployed as a Deployment pod in Kunernetes.
diff --git a/pkg/coilctl/cmd/root.go b/pkg/coilctl/cmd/root.go
index 226a39e8..76c10432 100644
--- a/pkg/coilctl/cmd/root.go
+++ b/pkg/coilctl/cmd/root.go
@@ -40,8 +40,9 @@ var etcdConfig *etcdutil.Config
 
 // rootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
-	Use:   "coilctl",
-	Short: "control and show coil settings",
+	Use:     "coilctl",
+	Version: coil.Version,
+	Short:   "control and show coil settings",
 	Long: `coilctl is a command-line tool to control and show coil settings.
 
 It directly communicates with etcd.  You need to prepare a
diff --git a/pkg/coild/cmd/root.go b/pkg/coild/cmd/root.go
index ef8f9997..f4a7a39c 100644
--- a/pkg/coild/cmd/root.go
+++ b/pkg/coild/cmd/root.go
@@ -54,8 +54,9 @@ var etcdConfig *etcdutil.Config
 
 // rootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
-	Use:   "coild",
-	Short: "Backend service to allocate IP address",
+	Use:     "coild",
+	Version: coil.Version,
+	Short:   "Backend service to allocate IP address",
 	Long: `coild is a backend service to allocate IP address.
 
 It normally run as a DaemonSet container in Kubernetes.
diff --git a/version.go b/version.go
new file mode 100644
index 00000000..9dda30f9
--- /dev/null
+++ b/version.go
@@ -0,0 +1,4 @@
+package coil
+
+// Version represents the version of coil
+const Version = "1.1.5"