diff --git a/genesis-builder/Cargo.toml b/genesis-builder/Cargo.toml
index 1c88ddeac2..99c8377c64 100644
--- a/genesis-builder/Cargo.toml
+++ b/genesis-builder/Cargo.toml
@@ -8,7 +8,7 @@ hex = "0.4"
 log = { package = "tracing", version = "0.1" }
 serde = "1.0"
 thiserror = "1.0"
-time = { version = "0.3", features = ["parsing", "serde"] }
+time = { version = "0.3", features = ["formatting", "parsing", "serde"] }
 toml = "0.7"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 
diff --git a/genesis-builder/src/config.rs b/genesis-builder/src/config.rs
index c4bd687d8b..21782fda55 100644
--- a/genesis-builder/src/config.rs
+++ b/genesis-builder/src/config.rs
@@ -25,7 +25,7 @@ pub struct GenesisConfig {
     pub parent_hash: Option<Blake2bHash>,
 
     /// Timestamp for the genesis block.
-    #[serde(deserialize_with = "time::serde::rfc3339::option::deserialize")]
+    #[serde(with = "time::serde::rfc3339::option")]
     pub timestamp: Option<OffsetDateTime>,
 
     /// The set of validators for the genesis state.