diff --git a/src/modules/chains/schemas.ts b/src/modules/chains/schemas.ts
index 39856a28..2f664742 100644
--- a/src/modules/chains/schemas.ts
+++ b/src/modules/chains/schemas.ts
@@ -67,6 +67,8 @@ const chainConfigSchemaBase = z.object({
   gasCacheDuration: z.number().default(30000), // TODO: Add schema
   feeHistoryBlockTagOverride: z.string().optional(),
   eip1559: z.boolean().default(false),
+  /** Optional minimum maxFeePerGas (wei) for legacy chains; RPC may reject below this (e.g. BSC). */
+  minMaxFeePerGas: bigIntLikeSchema.optional(),
   paymasterFunding: etherSchema.default("0.025"),
   paymasterFundingThreshold: etherSchema.default("0"),
   paymasterInitCode: hexSchema.optional(),
diff --git a/src/modules/gas-estimator/gas-estimator-v2.service.ts b/src/modules/gas-estimator/gas-estimator-v2.service.ts
index 9cc434ab..1b68571f 100644
--- a/src/modules/gas-estimator/gas-estimator-v2.service.ts
+++ b/src/modules/gas-estimator/gas-estimator-v2.service.ts
@@ -62,11 +62,18 @@ export class GasEstimatorServiceV2 {
           },
         )();
 
+        // Chain config may set a minimum (e.g. BSC); apply floor so RPC does not reject
+        const minGas = chainSettings.minMaxFeePerGas
+          ? BigInt(chainSettings.minMaxFeePerGas)
+          : 0n;
+        const effectiveGasPrice =
+          minGas > 0n && gasPrice < minGas ? minGas : gasPrice;
+
         conditions = {
-          maxFeePerGas: gasPrice,
-          maxPriorityFeePerGas: gasPrice,
+          maxFeePerGas: effectiveGasPrice,
+          maxPriorityFeePerGas: effectiveGasPrice,
           l1GasPrice: 0n,
-          baseFee: gasPrice,
+          baseFee: effectiveGasPrice,
         };
       } else {
         // EIP-1559 chain - use fee history for prediction