diff --git a/lib/app.js b/lib/app.js
index 4dda97d3..6d21ec5a 100644
--- a/lib/app.js
+++ b/lib/app.js
@@ -8,7 +8,6 @@ var routes = require('./routes');
 var plugins = require('./plugins');
 var db = require('./postgresql_interface');
 var logger = require('./logger');
-require('longjohn');
 
 module.exports = function(options) {
   var app = express();
diff --git a/lib/plugins.js b/lib/plugins.js
index 7b8803ec..f51a2c6f 100644
--- a/lib/plugins.js
+++ b/lib/plugins.js
@@ -4,11 +4,15 @@ var _ = require('lodash');
 var async   = require('async');
 var logger  = require('./logger');
 
+var argv = require('minimist')(process.argv.slice(2));
+
 var SATOSHI_FACTOR = 1e8;
 var POLLING_RATE = 60 * 1000; // poll each minute
 var REAP_RATE = 2 * 1000;
 var PENDING_TIMEOUT = 70 * 1000;
 
+if (argv.timeout) PENDING_TIMEOUT = argv.timeout / 1000;
+
 // TODO: might have to update this if user is allowed to extend monitoring time
 var DEPOSIT_TIMEOUT = 130 * 1000;
 
diff --git a/lib/postgresql_interface.js b/lib/postgresql_interface.js
index b128d9b5..9853b4c1 100644
--- a/lib/postgresql_interface.js
+++ b/lib/postgresql_interface.js
@@ -182,6 +182,7 @@ function bitcoinFractionalDigits(amount) {
 }
 
 function truncateBitcoins(bitcoins) {
+  if (bitcoins < 0) logger.error('Negative amount in truncateBitcoins');
   var decimalDigits = bitcoinFractionalDigits(bitcoins);
   var adjuster = Math.pow(10, decimalDigits);
   return (Math.round(bitcoins * adjuster) / adjuster);
@@ -339,12 +340,10 @@ function addPendingTx(client, session, incoming, currencyCode, toAddress,
     toAddress, satoshis];
   query(client, sql, values, function(err) {
 
-    // If pending tx already exists, do nothing
-    if (err && isUniqueViolation(err))
+    if (err && isUniqueViolation(err)) {
       return refreshPendingTx(client, session, cb);
-
-    if (err && !isUniqueViolation(err)) return cb(err);
-
+    }
+    if (err) return cb(err);
     cb();
   });
 }
@@ -429,15 +428,49 @@ exports.addIncomingTx = function addIncomingTx(session, tx, authority,
   });
 };
 
+function ensureNotFinal(client, session, cb) {
+  var sql = 'SELECT id FROM transactions ' +
+    'WHERE device_fingerprint=$1 AND session_id=$2 AND incoming=$3 ' +
+    'AND stage=$4' +
+    'LIMIT 1';
+  var values = [session.fingerprint, session.id, false, 'final_request'];
+
+  client.query(sql, values, function(err, results) {
+    var error;
+    if (err) return cb(err);
+    if (results.rows.length > 0) {
+      error = new Error('Final request already exists');
+      error.name = 'staleBill';
+      return cb(error);
+    }
+    cb();
+  });
+}
+
 exports.addOutgoingPending = function addOutgoingPending(session, currencyCode,
     toAddress, cb) {
   connect(function(cerr, client, done) {
     if (cerr) return cb(cerr);
 
-    addPendingTx(client, session, false, currencyCode, toAddress, 0,
-        function(err) {
-      done();
-      cb(err);
+    async.series([
+      async.apply(silentQuery, client, 'BEGIN', null),
+      async.apply(ensureNotFinal, client, session),
+      async.apply(addPendingTx, client, session, false, currencyCode, toAddress,
+        0)
+    ], function(err) {
+      if (err) {
+        rollback(client, done);
+        if (err.name === 'staleBill') {
+          logger.info('Received a bill insert after send coins request');
+          return cb();
+        }
+        logger.error(err);
+        return cb(err);
+      }
+      silentQuery(client, 'COMMIT', null, function() {
+        done();
+        cb();
+      });
     });
   });
 };