diff --git a/crates/driver/src/infra/solver/dto/solution.rs b/crates/driver/src/infra/solver/dto/solution.rs
index 3d344780c0..d916296867 100644
--- a/crates/driver/src/infra/solver/dto/solution.rs
+++ b/crates/driver/src/infra/solver/dto/solution.rs
@@ -197,7 +197,9 @@ impl Solutions {
                         .try_collect()?,
                     solver.clone(),
                     match solution.score {
-                        Score::Solver(score) => competition::solution::SolverScore::Solver(score),
+                        Score::Solver { score } => {
+                            competition::solution::SolverScore::Solver(score)
+                        }
                         Score::RiskAdjusted(success_probability) => {
                             competition::solution::SolverScore::RiskAdjusted(success_probability)
                         }
@@ -373,9 +375,13 @@ enum SigningScheme {
     Eip1271,
 }
 
+#[serde_as]
 #[derive(Debug, Deserialize)]
 #[serde(rename_all = "lowercase", deny_unknown_fields)]
 pub enum Score {
-    Solver(eth::U256),
+    Solver {
+        #[serde_as(as = "serialize::U256")]
+        score: eth::U256,
+    },
     RiskAdjusted(f64),
 }
diff --git a/crates/driver/src/tests/cases/score_competition.rs b/crates/driver/src/tests/cases/score_competition.rs
index 4c06082187..dbee014190 100644
--- a/crates/driver/src/tests/cases/score_competition.rs
+++ b/crates/driver/src/tests/cases/score_competition.rs
@@ -11,7 +11,7 @@ async fn solver_score_winner() {
     let test = setup()
         .pool(ab_pool())
         .order(ab_order())
-        .solution(ab_solution().score(Score::Solver(2902421280589416499u128.into()))) // not higher than objective value
+        .solution(ab_solution().score(Score::Solver { score: 2902421280589416499u128.into()})) // higher than objective value
         .solution(ab_solution().score(Score::RiskAdjusted(0.4)))
         .done()
         .await;
@@ -29,7 +29,9 @@ async fn risk_adjusted_score_winner() {
     let test = setup()
         .pool(ab_pool())
         .order(ab_order())
-        .solution(ab_solution().score(Score::Solver(DEFAULT_SCORE_MIN.into())))
+        .solution(ab_solution().score(Score::Solver {
+            score: DEFAULT_SCORE_MIN.into(),
+        }))
         .solution(ab_solution().score(Score::RiskAdjusted(0.9)))
         .done()
         .await;
diff --git a/crates/driver/src/tests/setup/mod.rs b/crates/driver/src/tests/setup/mod.rs
index 113996967e..09eef9c4d7 100644
--- a/crates/driver/src/tests/setup/mod.rs
+++ b/crates/driver/src/tests/setup/mod.rs
@@ -20,12 +20,13 @@ use {
             },
             setup::blockchain::Blockchain,
         },
-        util,
+        util::{self, serialize},
     },
     ethcontract::BlockId,
     hyper::StatusCode,
     itertools::Itertools,
     secp256k1::SecretKey,
+    serde_with::serde_as,
     std::{
         collections::{HashMap, HashSet},
         path::PathBuf,
@@ -54,10 +55,14 @@ pub enum Partial {
     },
 }
 
+#[serde_as]
 #[derive(Debug, Clone, serde::Serialize)]
 #[serde(rename_all = "lowercase")]
 pub enum Score {
-    Solver(eth::U256),
+    Solver {
+        #[serde_as(as = "serialize::U256")]
+        score: eth::U256,
+    },
     RiskAdjusted(f64),
 }
 
diff --git a/crates/solvers/src/api/routes/solve/dto/solution.rs b/crates/solvers/src/api/routes/solve/dto/solution.rs
index b80f6b52bc..8476716a95 100644
--- a/crates/solvers/src/api/routes/solve/dto/solution.rs
+++ b/crates/solvers/src/api/routes/solve/dto/solution.rs
@@ -133,7 +133,7 @@ impl Solutions {
                         })
                         .collect(),
                     score: match solution.score.clone() {
-                        solution::Score::Solver(score) => Score::Solver(score),
+                        solution::Score::Solver(score) => Score::Solver { score },
                         solution::Score::RiskAdjusted(score) => Score::RiskAdjusted(score.0),
                     },
                 })
@@ -319,9 +319,13 @@ enum SigningScheme {
 }
 
 /// A score for a solution. The score is used to rank solutions.
+#[serde_as]
 #[derive(Debug, Serialize)]
 #[serde(rename_all = "lowercase")]
 pub enum Score {
-    Solver(U256),
+    Solver {
+        #[serde_as(as = "serialize::U256")]
+        score: U256,
+    },
     RiskAdjusted(f64),
 }