diff --git a/package-lock.json b/package-lock.json
index a94cb80..636a1c5 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -14,6 +14,7 @@
         "dotenv": "^16.4.7",
         "ethers": "^5.8.0",
         "https-proxy-agent": "^7.0.6",
+        "undici": "^7.22.0",
         "ws": "^8.19.0"
       },
       "devDependencies": {
@@ -1828,6 +1829,15 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/undici": {
+      "version": "7.22.0",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-7.22.0.tgz",
+      "integrity": "sha512-RqslV2Us5BrllB+JeiZnK4peryVTndy9Dnqq62S3yYRRTj0tFQCwEniUy2167skdGOy3vqRzEvl1Dm4sV2ReDg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=20.18.1"
+      }
+    },
     "node_modules/undici-types": {
       "version": "5.26.5",
       "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-5.26.5.tgz",
diff --git a/package.json b/package.json
index aaf7d1e..9986f31 100644
--- a/package.json
+++ b/package.json
@@ -36,6 +36,7 @@
     "dotenv": "^16.4.7",
     "ethers": "^5.8.0",
     "https-proxy-agent": "^7.0.6",
+    "undici": "^7.22.0",
     "ws": "^8.19.0"
   },
   "devDependencies": {
diff --git a/src/services/ctf.js b/src/services/ctf.js
index 8672158..1592dd1 100644
--- a/src/services/ctf.js
+++ b/src/services/ctf.js
@@ -118,6 +118,9 @@ async function _doExecSafeCall(to, data, description = '') {
     if (description) logger.info(`MM: exec safe tx — ${description}`);
 
     let lastErr;
+    // Track gas price multiplier for replacement transactions
+    let gasMultiplier = 1;
+
     for (let attempt = 1; attempt <= MAX_RETRIES; attempt++) {
         try {
             const provider = await getPolygonProvider();
@@ -149,9 +152,15 @@ async function _doExecSafeCall(to, data, description = '') {
             // Polygon requires maxPriorityFeePerGas ≥ 25 Gwei.
             // Some RPC nodes (e.g. lava.build) return a stale low estimate, so we enforce a floor.
             const feeData = await provider.getFeeData();
-            const MIN_TIP = ethers.utils.parseUnits('30', 'gwei');
-            const gasTip = feeData.maxPriorityFeePerGas?.gt(MIN_TIP) ? feeData.maxPriorityFeePerGas : MIN_TIP;
-            const gasFeeCap = feeData.maxFeePerGas ?? ethers.utils.parseUnits('500', 'gwei');
+
+            // Increase gas price on retry to replace pending transaction
+            // Multiplier: 1x → 2x → 4x on subsequent attempts
+            const MIN_TIP = ethers.utils.parseUnits('30', 'gwei').mul(Math.ceil(gasMultiplier));
+            const gasTip = feeData.maxPriorityFeePerGas?.mul(Math.ceil(gasMultiplier)).gt(MIN_TIP)
+                ? feeData.maxPriorityFeePerGas.mul(Math.ceil(gasMultiplier))
+                : MIN_TIP;
+            const gasFeeCap = (feeData.maxFeePerGas ?? ethers.utils.parseUnits('500', 'gwei'))
+                .mul(Math.ceil(gasMultiplier * 1.5));
 
             const tx = await safe.execTransaction(
                 to, 0, data, 0, 0, 0, 0,
@@ -169,7 +178,14 @@ async function _doExecSafeCall(to, data, description = '') {
             const friendly = parseOnchainError(err);
 
             if (attempt < MAX_RETRIES) {
-                logger.warn(`MM: transaction failed (attempt ${attempt}/${MAX_RETRIES}): ${friendly} — retrying in ${RETRY_DELAY / 1000}s...`);
+                // Increase gas multiplier for replacement transaction
+                if (err?.message?.includes('replacement transaction underpriced') ||
+                    err?.message?.includes('Gas price too low to replace')) {
+                    gasMultiplier *= 2;
+                    logger.warn(`MM: transaction failed (attempt ${attempt}/${MAX_RETRIES}): ${friendly} — increasing gas ${gasMultiplier}x and retrying...`);
+                } else {
+                    logger.warn(`MM: transaction failed (attempt ${attempt}/${MAX_RETRIES}): ${friendly} — retrying in ${RETRY_DELAY / 1000}s...`);
+                }
                 await sleep(RETRY_DELAY);
             }
         }