diff --git a/yarn-project/foundation/src/log/bigint-utils.ts b/yarn-project/foundation/src/log/bigint-utils.ts
index 6cc94101ac2f..c9083ec1bfd0 100644
--- a/yarn-project/foundation/src/log/bigint-utils.ts
+++ b/yarn-project/foundation/src/log/bigint-utils.ts
@@ -11,6 +11,9 @@ export function convertBigintsToStrings(obj: unknown): unknown {
   }
 
   if (obj !== null && typeof obj === 'object') {
+    if (typeof (obj as any).toJSON === 'function') {
+      return convertBigintsToStrings((obj as any).toJSON());
+    }
     const result: Record<string, unknown> = {};
     for (const key in obj) {
       result[key] = convertBigintsToStrings((obj as Record<string, unknown>)[key]);
diff --git a/yarn-project/foundation/src/log/pino-logger.test.ts b/yarn-project/foundation/src/log/pino-logger.test.ts
index 9881535d4f58..22afc9e6a293 100644
--- a/yarn-project/foundation/src/log/pino-logger.test.ts
+++ b/yarn-project/foundation/src/log/pino-logger.test.ts
@@ -273,6 +273,35 @@ describe('pino-logger', () => {
     });
   });
 
+  it('serializes objects with toJSON() instead of dumping raw properties', () => {
+    const testLogger = createLogger('tojson-test');
+    capturingStream.clear();
+
+    // Simulate an EthAddress-like object with an internal buffer and a toJSON method
+    const addressLike = {
+      buffer: Buffer.from('1234567890abcdef1234567890abcdef12345678', 'hex'),
+      toJSON() {
+        return '0x1234567890abcdef1234567890abcdef12345678';
+      },
+    };
+
+    testLogger.info('address logging test', {
+      validator: addressLike,
+      nested: { addr: addressLike },
+      array: [addressLike],
+      plainString: 'hello',
+    });
+
+    const entries = capturingStream.getJsonLines();
+    expect(entries).toHaveLength(1);
+    expect(entries[0]).toMatchObject({
+      validator: '0x1234567890abcdef1234567890abcdef12345678',
+      nested: { addr: '0x1234567890abcdef1234567890abcdef12345678' },
+      array: ['0x1234567890abcdef1234567890abcdef12345678'],
+      plainString: 'hello',
+    });
+  });
+
   it('returns bindings via getBindings', () => {
     const testLogger = createLogger('bindings-test', { actor: 'main', instanceId: 'id-123' });
     const bindings = testLogger.getBindings();
diff --git a/yarn-project/slasher/src/tally_slasher_client.ts b/yarn-project/slasher/src/tally_slasher_client.ts
index 70ef6fdfeeb6..d95d565746a8 100644
--- a/yarn-project/slasher/src/tally_slasher_client.ts
+++ b/yarn-project/slasher/src/tally_slasher_client.ts
@@ -349,15 +349,11 @@ export class TallySlasherClient implements ProposerSlashActionProvider, SlasherC
       return undefined;
     }
 
-    const offensesToSlashLog = offensesToSlash.map(offense => ({
-      ...offense,
-      amount: offense.amount.toString(),
-    }));
     this.log.info(`Voting to slash ${offensesToSlash.length} offenses`, {
       slotNumber,
       currentRound,
       slashedRound,
-      offensesToSlash: offensesToSlashLog,
+      offensesToSlash,
     });
 
     const committees = await this.collectCommitteesActiveDuringRound(slashedRound);