diff --git a/idna/Cargo.toml b/idna/Cargo.toml
index 7fd9a53f1..0d0c750b3 100644
--- a/idna/Cargo.toml
+++ b/idna/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "idna"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["The rust-url developers"]
 description = "IDNA (Internationalizing Domain Names in Applications) and Punycode."
 categories = ["no_std"]