diff --git a/Cargo.lock b/Cargo.lock
index edb5cc7..2b09bde 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,7 +4,7 @@ version = 3
 
 [[package]]
 name = "error-iter"
-version = "0.3.0"
+version = "0.4.0"
 dependencies = [
  "thiserror",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 80dcbb8..3a26828 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,7 @@
 name = "error-iter"
 description = "Error::sources on stable Rust"
 repository = "https://github.com/parasyte/error-iter"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Jay Oster <jay@kodewerx.org>"]
 edition = "2018"
 readme = "README.md"