diff --git a/cmd_bind.go b/cmd_bind.go
index 7a7db8e..55d6466 100644
--- a/cmd_bind.go
+++ b/cmd_bind.go
@@ -31,7 +31,7 @@ ex:
 		Flag: *flag.NewFlagSet("gopy-bind", flag.ExitOnError),
 	}
 
-	cmd.Flag.String("lang", "py2", "python version to use for bindings (python2|py2|python3|py3)")
+	cmd.Flag.String("lang", defaultPyVersion, "python version to use for bindings (python2|py2|python3|py3)")
 	cmd.Flag.String("output", "", "output directory for bindings")
 	return cmd
 }
diff --git a/cmd_gen.go b/cmd_gen.go
index f0e526b..1510b3f 100644
--- a/cmd_gen.go
+++ b/cmd_gen.go
@@ -29,7 +29,7 @@ ex:
 		Flag: *flag.NewFlagSet("gopy-gen", flag.ExitOnError),
 	}
 
-	cmd.Flag.String("lang", "python", "target language for bindings")
+	cmd.Flag.String("lang", defaultPyVersion, "target language for bindings")
 	cmd.Flag.String("output", "", "output directory for bindings")
 	return cmd
 }
diff --git a/main.go b/main.go
index 6f078aa..c8d1eec 100644
--- a/main.go
+++ b/main.go
@@ -12,6 +12,10 @@ import (
 	"github.com/gonuts/flag"
 )
 
+const (
+	defaultPyVersion = "py2"
+)
+
 var (
 	app *commander.Command
 )