diff --git a/README.md b/README.md
index 87c0307..cf77f1c 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,7 @@ KRAKEN_API_KEY="apiKeyFromTheKrakenSettings"
 KRAKEN_API_SECRET="privateKeyFromTheKrakenSettings"
 
 # used for buying
+KRAKEN_ORDER_TYPE="market" # "limit" (default) or "market"
 KRAKEN_API_FIAT="USD" # the governmental shitcoin you are selling
 KRAKEN_BUY_AMOUNT=21 # fiat amount you trade for the future of money
 
@@ -138,6 +139,7 @@ set -e
 
 export KRAKEN_API_KEY="apiKeyFromTheKrakenSettings"
 export KRAKEN_API_SECRET="privateKeyFromTheKrakenSettings"
+export KRAKEN_ORDER_TYPE="market"
 export KRAKEN_API_FIAT="USD"
 export KRAKEN_BUY_AMOUNT=21
 export KRAKEN_MAX_REL_FEE=0.5
diff --git a/commands/stack.js b/commands/stack.js
index 7d223c6..727a320 100644
--- a/commands/stack.js
+++ b/commands/stack.js
@@ -1,5 +1,6 @@
-module.exports = async (kraken, validate, getEnv) => {
+module.exports = async (kraken, validate, { getEnv, getEnvOpt }) => {
   const [fiat, amount] = getEnv('KRAKEN_API_FIAT', 'KRAKEN_BUY_AMOUNT')
+  const ordertype = getEnvOpt('KRAKEN_ORDER_TYPE', 'limit', ['limit', 'market'])
 
   // https://www.kraken.com/features/api
   const crypto = 'XBT'
@@ -24,7 +25,7 @@ module.exports = async (kraken, validate, getEnv) => {
   console.log('📉  Bid:', bid, fiat, '\n')
 
   // Place order
-  const details = { pair, type: 'buy', ordertype: 'limit', price, volume }
+  const details = { pair, type: 'buy', ordertype, price, volume }
   if (validate) details.validate = true
 
   const { result: { descr: { order }, txid } } = await kraken.api('AddOrder', details)
diff --git a/commands/withdraw.js b/commands/withdraw.js
index 154f4cc..e88c656 100644
--- a/commands/withdraw.js
+++ b/commands/withdraw.js
@@ -1,4 +1,4 @@
-module.exports = async (kraken, validate, getEnv) => {
+module.exports = async (kraken, validate, { getEnv }) => {
   const [maxFee, key] = getEnv('KRAKEN_MAX_REL_FEE', 'KRAKEN_WITHDRAW_KEY')
 
   // https://api.kraken.com/0/private/WithdrawInfo
diff --git a/index.js b/index.js
index 7569f4f..a37667b 100644
--- a/index.js
+++ b/index.js
@@ -6,6 +6,11 @@ const getEnv = (...vars) => vars.map(name => {
   assert(value, `Provide the ${name} environment variable.`)
   return value
 })
+const getEnvOpt = (varname, defaultValue, allowedValues) => {
+  const value = process.env[varname] || defaultValue
+  if (allowedValues) assert(allowedValues.includes(value), `The ${varname} environment variable must be one of ${allowedValues.map(v => `"${v}"`).join(", ")}.`)
+  return value
+}
 const command = process.argv[2].replace('--cmd=', '')
 const validate = process.argv.includes('--validate') || process.env['KRAKEN_DRY_RUN_PLACE_NO_ORDER']
 
@@ -15,7 +20,7 @@ const validate = process.argv.includes('--validate') || process.env['KRAKEN_DRY_
     const kraken = new Kraken(apiKey, secret)
 
     const cmd = require(`./commands/${command}`)
-    await cmd(kraken, validate, getEnv)
+    await cmd(kraken, validate, { getEnv, getEnvOpt })
 
     if (validate) console.log('\n🚨  THIS WAS JUST A VALIDATION RUN!')
   } catch (err) {