diff --git a/Cargo.toml b/Cargo.toml
index 6151101..bc9c310 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "cf-rustracing"
-version = "1.3.0"
+version = "1.4.0"
 authors = ["Takeru Ohta <phjgt308@gmail.com>", "Cloudflare Inc."]
 description = "OpenTracing API for Rust"
 homepage = "https://github.com/cloudflare/rustracing"