diff --git a/Cargo.lock b/Cargo.lock
index 9ff4bc10582..36faa7c80f1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1086,9 +1086,9 @@ dependencies = [
 
 [[package]]
 name = "hex"
-version = "0.3.2"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "805026a5d0141ffc30abb3be3173848ad46a1b1664fe632428479619a3644d77"
+checksum = "644f9158b2f133fd50f5fb3242878846d9eb792e445c893805ff0e3824006e35"
 
 [[package]]
 name = "hostname"
diff --git a/Cargo.toml b/Cargo.toml
index f09280a1909..a90e0944977 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -41,7 +41,7 @@ openssl = "0.10.13"
 oauth2 = "2.0.0"
 log = "0.4"
 env_logger = "0.7"
-hex = "0.3"
+hex = "0.4"
 htmlescape = "0.3.1"
 license-exprs = "^1.4"
 dotenv = "0.15"
diff --git a/src/controllers/krate/publish.rs b/src/controllers/krate/publish.rs
index 3322ec0e365..93f3e1d5a50 100644
--- a/src/controllers/krate/publish.rs
+++ b/src/controllers/krate/publish.rs
@@ -192,8 +192,7 @@ pub fn publish(req: &mut dyn Request) -> AppResult<Response> {
             .uploader
             .upload_crate(req, &krate, maximums, vers)?;
 
-        let mut hex_cksum = String::new();
-        cksum.write_hex(&mut hex_cksum)?;
+        let hex_cksum = cksum.encode_hex::<String>();
 
         // Register this crate in our local git repo.
         let git_crate = git::Crate {