diff --git a/lib/bcoin/http/server.js b/lib/bcoin/http/server.js
index 392260c9..4031d043 100644
--- a/lib/bcoin/http/server.js
+++ b/lib/bcoin/http/server.js
@@ -230,6 +230,12 @@ HTTPServer.prototype._init = function _init() {
       assert(utils.isUInt32(options.age), 'Age must be a number.');
     }
 
+    if (params.fee)
+      options.fee = utils.satoshi(params.fee);
+
+    if (params.maxFee)
+      options.maxFee = utils.satoshi(params.maxFee);
+
     if (params.rate)
       options.rate = utils.satoshi(params.rate);
 
diff --git a/lib/bcoin/mtx.js b/lib/bcoin/mtx.js
index 73113b2e..434cbec6 100644
--- a/lib/bcoin/mtx.js
+++ b/lib/bcoin/mtx.js
@@ -1250,7 +1250,7 @@ MTX.prototype.selectCoins = function selectCoins(coins, options) {
     // bytes (10000 satoshi for every 1024 bytes).
     do {
       // Calculate max possible size after signing.
-      size = tx.maxSize(options.key, options.script);
+      size = tx.maxSize(options);
 
       if (tryFree && options.height >= 0) {
         // Note that this will only work
@@ -1272,6 +1272,13 @@ MTX.prototype.selectCoins = function selectCoins(coins, options) {
       if (fee > constants.tx.MAX_FEE)
         fee = constants.tx.MAX_FEE;
 
+      if (options.maxFee && fee > options.maxFee) {
+        throw new FundingError(
+          'Fee is too high.',
+          tx.getInputValue(),
+          total());
+      }
+
       // Failed to get enough funds, add more coins.
       if (!isFull())
         addCoins();