diff --git a/test-mutation/config.json b/test-mutation/config.json
index efdf720af..e5a290ade 100644
--- a/test-mutation/config.json
+++ b/test-mutation/config.json
@@ -1,10 +1,22 @@
 [
   {
-    "filename": "../contracts/tokenbridge/arbitrum/gateway/L2ArbitrumGateway.sol",
+    "filename": "../contracts/tokenbridge/ethereum/L1ArbitrumMessenger.sol",
     "sourceroot": "..",
     "solc_remappings": [
       "@openzeppelin=../node_modules/@openzeppelin",
       "@arbitrum=../node_modules/@arbitrum"
-    ]
+    ],
+    "num_mutants": 4,
+    "random_seed": true
+  },
+  {
+    "filename": "../contracts/tokenbridge/ethereum/gateway/L1ArbitrumExtendedGateway.sol",
+    "sourceroot": "..",
+    "solc_remappings": [
+      "@openzeppelin=../node_modules/@openzeppelin",
+      "@arbitrum=../node_modules/@arbitrum"
+    ],
+    "num_mutants": 4,
+    "random_seed": true
   }
 ]
diff --git a/test-mutation/gambitTester.ts b/test-mutation/gambitTester.ts
index 165cfa708..4cc12c188 100644
--- a/test-mutation/gambitTester.ts
+++ b/test-mutation/gambitTester.ts
@@ -46,7 +46,7 @@ async function runMutationTesting() {
   console.log('====== Generating mutants')
   const mutants: Mutant[] = await _generateMutants()
 
-  console.log('\n====== Test mutants')
+  console.log('\n====== Testing mutants')
   const results = await _testAllMutants(mutants)
 
   // Print summary
@@ -74,6 +74,9 @@ async function _generateMutants(): Promise<Mutant[]> {
     fs.readFileSync(`${GAMBIT_OUT}/gambit_results.json`, 'utf8')
   )
   console.log(`Generated ${mutants.length} mutants in ${GAMBIT_OUT}`)
+  console.log('----------------------------------------------')
+  console.log('Mutants overview:')
+  console.log(fs.readFileSync(`${GAMBIT_OUT}/mutants.log`, 'utf8'))
 
   return mutants
 }