diff --git a/beacon_node/execution_layer/src/engine_api/json_structures.rs b/beacon_node/execution_layer/src/engine_api/json_structures.rs
index 28eb90fd1f..034483eb73 100644
--- a/beacon_node/execution_layer/src/engine_api/json_structures.rs
+++ b/beacon_node/execution_layer/src/engine_api/json_structures.rs
@@ -838,10 +838,10 @@ impl TryFrom<JsonClientVersionV1> for ClientVersionV1 {
 pub struct JsonDepositRequest {
     pub pubkey: PublicKeyBytes,
     pub withdrawal_credentials: Hash256,
-    #[serde(with = "serde_utils::quoted_u64")]
+    #[serde(with = "serde_utils::u64_hex_be")]
     pub amount: u64,
     pub signature: Signature,
-    #[serde(with = "serde_utils::quoted_u64")]
+    #[serde(with = "serde_utils::u64_hex_be")]
     pub index: u64,
 }
 
@@ -874,7 +874,7 @@ impl From<JsonDepositRequest> for DepositReceipt {
 pub struct JsonWithdrawalRequest {
     pub source_address: Address,
     pub validator_public_key: PublicKeyBytes,
-    #[serde(with = "serde_utils::quoted_u64")]
+    #[serde(with = "serde_utils::u64_hex_be")]
     pub amount: u64,
 }