diff --git a/Cargo.toml b/Cargo.toml
index 0151e09..68f0c52 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,7 +21,7 @@ futures = "0.3"
 hotshot-types = { git = "https://github.com/EspressoSystems/HotShot.git", tag = "0.5.28" }
 serde = { version = "1.0", features = ["derive"] }
 snafu = "0.8"
-tagged-base64 = { git = "https://github.com/EspressoSystems/tagged-base64", tag = "0.3.4" }
+tagged-base64 = { git = "https://github.com/EspressoSystems/tagged-base64", tag = "v0.4.0" }
 tide-disco = { git = "https://github.com/EspressoSystems/tide-disco.git", tag = "v0.5.0" }
 toml = "0.8"
 versioned-binary-serialization = { git = "https://github.com/EspressoSystems/versioned-binary-serialization", tag = "0.1.2" }