diff --git a/crates/autopilot/src/infra/solvers/dto/reveal.rs b/crates/autopilot/src/infra/solvers/dto/reveal.rs
index f963fce1a5..41971d28b1 100644
--- a/crates/autopilot/src/infra/solvers/dto/reveal.rs
+++ b/crates/autopilot/src/infra/solvers/dto/reveal.rs
@@ -9,7 +9,6 @@ use {
 #[serde(rename_all = "camelCase")]
 pub struct Request {
     /// Unique ID of the solution (per driver competition), to reveal.
-    #[serde_as(as = "serde_with::DisplayFromStr")]
     pub solution_id: u64,
     /// Auction ID in which the specified solution ID is competing.
     #[serde_as(as = "Option<serde_with::DisplayFromStr>")]
diff --git a/crates/autopilot/src/infra/solvers/dto/settle.rs b/crates/autopilot/src/infra/solvers/dto/settle.rs
index 3abdf15dbe..5277eef76e 100644
--- a/crates/autopilot/src/infra/solvers/dto/settle.rs
+++ b/crates/autopilot/src/infra/solvers/dto/settle.rs
@@ -9,7 +9,6 @@ use {
 #[serde(rename_all = "camelCase")]
 pub struct Request {
     /// Unique ID of the solution (per driver competition), to settle.
-    #[serde_as(as = "serde_with::DisplayFromStr")]
     pub solution_id: u64,
     /// The last block number in which the solution TX can be included
     pub submission_deadline_latest_block: u64,
diff --git a/crates/autopilot/src/infra/solvers/dto/solve.rs b/crates/autopilot/src/infra/solvers/dto/solve.rs
index a54c143f70..ad793a7f2f 100644
--- a/crates/autopilot/src/infra/solvers/dto/solve.rs
+++ b/crates/autopilot/src/infra/solvers/dto/solve.rs
@@ -170,7 +170,6 @@ pub enum Side {
 pub struct Solution {
     /// Unique ID of the solution (per driver competition), used to identify
     /// it in subsequent requests (reveal, settle).
-    #[serde(deserialize_with = "deserialize_solution_id")]
     pub solution_id: u64,
     #[serde_as(as = "HexOrDecimalU256")]
     pub score: U256,
@@ -182,37 +181,6 @@ pub struct Solution {
     pub gas: Option<u64>,
 }
 
-fn deserialize_solution_id<'de, D>(deserializer: D) -> Result<u64, D::Error>
-where
-    D: serde::Deserializer<'de>,
-{
-    struct SolutionIdVisitor;
-
-    impl serde::de::Visitor<'_> for SolutionIdVisitor {
-        type Value = u64;
-
-        fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-            formatter.write_str("a string or integer representing a solution ID")
-        }
-
-        fn visit_u64<E>(self, value: u64) -> Result<u64, E>
-        where
-            E: serde::de::Error,
-        {
-            Ok(value)
-        }
-
-        fn visit_str<E>(self, value: &str) -> Result<u64, E>
-        where
-            E: serde::de::Error,
-        {
-            value.parse::<u64>().map_err(serde::de::Error::custom)
-        }
-    }
-
-    deserializer.deserialize_any(SolutionIdVisitor)
-}
-
 #[derive(Clone, Debug, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct Response {
diff --git a/crates/driver/src/infra/api/routes/mod.rs b/crates/driver/src/infra/api/routes/mod.rs
index 434846385e..ee1027b0e9 100644
--- a/crates/driver/src/infra/api/routes/mod.rs
+++ b/crates/driver/src/infra/api/routes/mod.rs
@@ -15,34 +15,3 @@ pub(super) use {
     settle::settle,
     solve::{solve, AuctionError},
 };
-
-pub(crate) fn deserialize_solution_id<'de, D>(deserializer: D) -> Result<u64, D::Error>
-where
-    D: serde::Deserializer<'de>,
-{
-    struct SolutionIdVisitor;
-
-    impl serde::de::Visitor<'_> for SolutionIdVisitor {
-        type Value = u64;
-
-        fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-            formatter.write_str("a string or integer representing a solution ID")
-        }
-
-        fn visit_u64<E>(self, value: u64) -> Result<u64, E>
-        where
-            E: serde::de::Error,
-        {
-            Ok(value)
-        }
-
-        fn visit_str<E>(self, value: &str) -> Result<u64, E>
-        where
-            E: serde::de::Error,
-        {
-            value.parse::<u64>().map_err(serde::de::Error::custom)
-        }
-    }
-
-    deserializer.deserialize_any(SolutionIdVisitor)
-}
diff --git a/crates/driver/src/infra/api/routes/reveal/dto/solution.rs b/crates/driver/src/infra/api/routes/reveal/dto/solution.rs
index 0c8d55fa49..b0a75e1e1c 100644
--- a/crates/driver/src/infra/api/routes/reveal/dto/solution.rs
+++ b/crates/driver/src/infra/api/routes/reveal/dto/solution.rs
@@ -1,11 +1,10 @@
-use {super::super::super::deserialize_solution_id, serde::Deserialize, serde_with::serde_as};
+use {serde::Deserialize, serde_with::serde_as};
 
 #[serde_as]
 #[derive(Debug, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct Solution {
     /// Unique ID of the solution (per driver competition), to reveal.
-    #[serde(deserialize_with = "deserialize_solution_id")]
     pub solution_id: u64,
     /// Auction ID in which the specified solution ID is competing.
     #[serde_as(as = "Option<serde_with::DisplayFromStr>")]
diff --git a/crates/driver/src/infra/api/routes/settle/dto/solution.rs b/crates/driver/src/infra/api/routes/settle/dto/solution.rs
index 6c62cd0cdd..fbe8ea4501 100644
--- a/crates/driver/src/infra/api/routes/settle/dto/solution.rs
+++ b/crates/driver/src/infra/api/routes/settle/dto/solution.rs
@@ -1,11 +1,10 @@
-use {super::super::super::deserialize_solution_id, serde::Deserialize, serde_with::serde_as};
+use {serde::Deserialize, serde_with::serde_as};
 
 #[serde_as]
 #[derive(Debug, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct Solution {
     /// Unique ID of the solution (per driver competition), to settle.
-    #[serde(deserialize_with = "deserialize_solution_id")]
     pub solution_id: u64,
     /// The last block number in which the solution TX can be included
     pub submission_deadline_latest_block: u64,
diff --git a/crates/driver/src/tests/cases/buy_eth.rs b/crates/driver/src/tests/cases/buy_eth.rs
index 204dc7b2bd..35bf50f699 100644
--- a/crates/driver/src/tests/cases/buy_eth.rs
+++ b/crates/driver/src/tests/cases/buy_eth.rs
@@ -16,5 +16,5 @@ async fn test() {
         .await;
 
     let id = test.solve().await.ok().orders(&[order]).id();
-    test.settle(&id).await.ok().await.eth_order_executed().await;
+    test.settle(id).await.ok().await.eth_order_executed().await;
 }
diff --git a/crates/driver/src/tests/cases/merge_settlements.rs b/crates/driver/src/tests/cases/merge_settlements.rs
index ae27ac6f4b..8c16ecaa6f 100644
--- a/crates/driver/src/tests/cases/merge_settlements.rs
+++ b/crates/driver/src/tests/cases/merge_settlements.rs
@@ -35,8 +35,8 @@ async fn possible() {
         .await;
 
     let id = test.solve().await.ok().orders(&[ab_order, cd_order]).id();
-    test.reveal(&id).await.ok().calldata();
-    test.settle(&id)
+    test.reveal(id).await.ok().calldata();
+    test.settle(id)
         .await
         // Even though the solver returned two solutions, the executed settlement is a
         // combination of the two, meaning the settlements were merged successfully.
@@ -91,8 +91,8 @@ async fn impossible() {
 
     // Only the first A-B order gets settled.
     let id = test.solve().await.ok().orders(&[order]).id();
-    test.reveal(&id).await.ok().calldata();
-    test.settle(&id).await.ok().await.ab_order_executed().await;
+    test.reveal(id).await.ok().calldata();
+    test.settle(id).await.ok().await.ab_order_executed().await;
 }
 
 /// Test that mergable solutions don't get merged if feature was not enabled.
@@ -114,6 +114,6 @@ async fn possible_but_forbidden() {
     // Even though the solutions could be combined (see test "possible") they were
     // not because solution merging is not enabled by default.
     let id = test.solve().await.ok().orders(&[ab_order]).id();
-    test.reveal(&id).await.ok().calldata();
-    test.settle(&id).await.ok().await.ab_order_executed().await;
+    test.reveal(id).await.ok().calldata();
+    test.settle(id).await.ok().await.ab_order_executed().await;
 }
diff --git a/crates/driver/src/tests/cases/multiple_solutions.rs b/crates/driver/src/tests/cases/multiple_solutions.rs
index f5da54e33b..33c78efd5d 100644
--- a/crates/driver/src/tests/cases/multiple_solutions.rs
+++ b/crates/driver/src/tests/cases/multiple_solutions.rs
@@ -18,7 +18,7 @@ async fn valid() {
         .await;
 
     let id = test.solve().await.ok().orders(&[order]).id();
-    test.reveal(&id).await.ok().calldata();
+    test.reveal(id).await.ok().calldata();
 }
 
 /// Test that the invalid solution is discarded when the /solve endpoint
@@ -36,5 +36,5 @@ async fn invalid() {
         .await;
 
     let id = test.solve().await.ok().orders(&[order]).id();
-    test.reveal(&id).await.ok().calldata();
+    test.reveal(id).await.ok().calldata();
 }
diff --git a/crates/driver/src/tests/cases/parallel_auctions.rs b/crates/driver/src/tests/cases/parallel_auctions.rs
index 12445d2f8b..cac7e3f186 100644
--- a/crates/driver/src/tests/cases/parallel_auctions.rs
+++ b/crates/driver/src/tests/cases/parallel_auctions.rs
@@ -25,25 +25,25 @@ async fn driver_handles_solutions_based_on_id() {
 
     // calling `/reveal` or `/settle` with incorrect solution ids
     // results in an error.
-    test.settle("99").await.err().kind("SolutionNotAvailable");
-    test.reveal("99").await.err().kind("SolutionNotAvailable");
+    test.settle(99).await.err().kind("SolutionNotAvailable");
+    test.reveal(99).await.err().kind("SolutionNotAvailable");
 
     // calling `/reveal` or `/settle` with a reasonable id works
     // but wrong auction id results in an error.
     test.set_auction_id(100);
-    test.reveal(&solution_id)
+    test.reveal(solution_id)
         .await
         .err()
         .kind("SolutionNotAvailable");
-    test.settle(&solution_id)
+    test.settle(solution_id)
         .await
         .err()
         .kind("SolutionNotAvailable");
 
     // calling `/reveal` or `/settle` with a reasonable id works.
     test.set_auction_id(1);
-    test.reveal(&solution_id).await.ok();
-    test.settle(&solution_id)
+    test.reveal(solution_id).await.ok();
+    test.settle(solution_id)
         .await
         .ok()
         .await
@@ -52,11 +52,11 @@ async fn driver_handles_solutions_based_on_id() {
 
     // calling `/reveal` or `/settle` with for a legit solution that
     // has already been settled also fails.
-    test.settle(&solution_id)
+    test.settle(solution_id)
         .await
         .err()
         .kind("SolutionNotAvailable");
-    test.reveal(&solution_id)
+    test.reveal(solution_id)
         .await
         .err()
         .kind("SolutionNotAvailable");
@@ -89,12 +89,7 @@ async fn driver_can_settle_old_solutions() {
     // Technically this is not super convincing since all remembered solutions
     // are identical but this is the best we are going to get without needing
     // to heavily modify the testing framework.
-    test.settle(&id1)
-        .await
-        .ok()
-        .await
-        .eth_order_executed()
-        .await;
+    test.settle(id1).await.ok().await.eth_order_executed().await;
 }
 
 /// Tests that the driver only remembers a relatively small number of solutions.
@@ -118,12 +113,12 @@ async fn driver_has_a_short_memory() {
     let id6 = test.solve().await.ok().id();
 
     // recalling the 5 most recent solutions works
-    test.reveal(&id2).await.ok();
-    test.reveal(&id3).await.ok();
-    test.reveal(&id4).await.ok();
-    test.reveal(&id5).await.ok();
-    test.reveal(&id6).await.ok();
+    test.reveal(id2).await.ok();
+    test.reveal(id3).await.ok();
+    test.reveal(id4).await.ok();
+    test.reveal(id5).await.ok();
+    test.reveal(id6).await.ok();
 
     // recalling an older solution doesn't work
-    test.reveal(&id1).await.err().kind("SolutionNotAvailable");
+    test.reveal(id1).await.err().kind("SolutionNotAvailable");
 }
diff --git a/crates/driver/src/tests/cases/settle.rs b/crates/driver/src/tests/cases/settle.rs
index 110d138734..fd50e1779c 100644
--- a/crates/driver/src/tests/cases/settle.rs
+++ b/crates/driver/src/tests/cases/settle.rs
@@ -30,7 +30,7 @@ async fn matrix() {
                 .await;
 
             let id = test.solve().await.ok().id();
-            test.settle(&id).await.ok().await.ab_order_executed().await;
+            test.settle(id).await.ok().await.ab_order_executed().await;
         }
     }
 }
@@ -47,7 +47,7 @@ async fn solution_not_available() {
         .done()
         .await;
 
-    test.settle("99").await.err().kind("SolutionNotAvailable");
+    test.settle(99).await.err().kind("SolutionNotAvailable");
 }
 
 /// Checks that settlements with revert risk are not submitted via public
@@ -71,7 +71,7 @@ async fn private_rpc_with_high_risk_solution() {
 
     let id = test.solve().await.ok().id();
     // Public cannot be used and private RPC is not available
-    test.settle(&id).await.err().kind("FailedToSubmit");
+    test.settle(id).await.err().kind("FailedToSubmit");
 }
 
 #[tokio::test]
@@ -108,5 +108,5 @@ async fn high_gas_limit() {
         .execute("evm_setBlockGasLimit", vec![serde_json::json!(9_000_000)])
         .await
         .unwrap();
-    test.settle(&id).await.ok().await;
+    test.settle(id).await.ok().await;
 }
diff --git a/crates/driver/src/tests/cases/solver_balance.rs b/crates/driver/src/tests/cases/solver_balance.rs
index 04a12b4408..3294d3405e 100644
--- a/crates/driver/src/tests/cases/solver_balance.rs
+++ b/crates/driver/src/tests/cases/solver_balance.rs
@@ -42,7 +42,7 @@ async fn test_just_enough_funded() {
         .await;
 
     let id = test.solve_with_solver("barely_funded").await.ok().id();
-    test.settle_with_solver("barely_funded", &id)
+    test.settle_with_solver("barely_funded", id)
         .await
         .ok()
         .await;
diff --git a/crates/driver/src/tests/setup/driver.rs b/crates/driver/src/tests/setup/driver.rs
index 6cf08b1cc6..cd7115fe38 100644
--- a/crates/driver/src/tests/setup/driver.rs
+++ b/crates/driver/src/tests/setup/driver.rs
@@ -147,7 +147,7 @@ pub fn solve_req(test: &Test) -> serde_json::Value {
 }
 
 /// Create a request for the driver /reveal endpoint.
-pub fn reveal_req(solution_id: &str, auction_id: &str) -> serde_json::Value {
+pub fn reveal_req(solution_id: u64, auction_id: &str) -> serde_json::Value {
     json!({
         "solutionId": solution_id,
         "auctionId": auction_id,
@@ -157,7 +157,7 @@ pub fn reveal_req(solution_id: &str, auction_id: &str) -> serde_json::Value {
 /// Create a request for the driver /settle endpoint.
 pub fn settle_req(
     submission_deadline_latest_block: u64,
-    solution_id: &str,
+    solution_id: u64,
     auction_id: &str,
 ) -> serde_json::Value {
     json!({
diff --git a/crates/driver/src/tests/setup/mod.rs b/crates/driver/src/tests/setup/mod.rs
index 171ebc6261..dc22169e29 100644
--- a/crates/driver/src/tests/setup/mod.rs
+++ b/crates/driver/src/tests/setup/mod.rs
@@ -1039,7 +1039,7 @@ impl Test {
     }
 
     /// Call the /reveal endpoint.
-    pub async fn reveal(&self, solution_id: &str) -> Reveal {
+    pub async fn reveal(&self, solution_id: u64) -> Reveal {
         let res = self
             .client
             .post(format!(
@@ -1089,11 +1089,11 @@ impl Test {
     }
 
     /// Call the /settle endpoint.
-    pub async fn settle(&self, solution_id: &str) -> Settle {
+    pub async fn settle(&self, solution_id: u64) -> Settle {
         self.settle_with_solver(solver::NAME, solution_id).await
     }
 
-    pub async fn settle_with_solver(&self, solver_name: &str, solution_id: &str) -> Settle {
+    pub async fn settle_with_solver(&self, solver_name: &str, solution_id: u64) -> Settle {
         /// The maximum number of blocks to wait for a settlement to appear on
         /// chain.
         const SUBMISSION_DEADLINE: u64 = 3;
@@ -1213,13 +1213,12 @@ impl SolveOk<'_> {
 
     /// Extracts the solution id from the response. Since response can contain
     /// multiple solutions, it takes the id from the first solution.
-    pub fn id(&self) -> String {
+    pub fn id(&self) -> u64 {
         let solution = self.solution();
         solution
             .get("solutionId")
             .unwrap()
             .as_u64()
-            .map(|id| id.to_string())
             .unwrap()
             .to_owned()
     }