diff --git a/__tests__/customConfig.test.js b/__tests__/customConfig.test.js
index b757dff25..6eec9c94d 100644
--- a/__tests__/customConfig.test.js
+++ b/__tests__/customConfig.test.js
@@ -1,7 +1,20 @@
+import fs from 'fs'
 import path from 'path'
 import postcss from 'postcss'
 import tailwind from '../src/index'
 
+function inTempDirectory(callback) {
+  return new Promise(resolve => {
+    fs.mkdirSync(path.resolve('./__tmp'))
+    process.chdir(path.resolve('./__tmp'))
+    callback().then(() => {
+      process.chdir(path.resolve('../'))
+      fs.rmdirSync(path.resolve('./__tmp'))
+      resolve()
+    })
+  })
+}
+
 test('it uses the values from the custom config file', () => {
   return postcss([tailwind(path.resolve(`${__dirname}/fixtures/custom-config.js`))])
     .process(
@@ -25,7 +38,6 @@ test('it uses the values from the custom config file', () => {
           }
         }
       `
-
       expect(result.css).toMatchCss(expected)
     })
 })
@@ -65,3 +77,43 @@ test('custom config can be passed as an object', () => {
       expect(result.css).toMatchCss(expected)
     })
 })
+
+test('tailwind.config.js is picked up by default', () => {
+  return inTempDirectory(() => {
+    fs.writeFileSync(
+      path.resolve('./tailwind.config.js'),
+      `module.exports = {
+        theme: {
+          screens: {
+            mobile: '400px',
+          },
+        },
+      }`
+    )
+
+    return postcss([tailwind])
+      .process(
+        `
+          @responsive {
+            .foo {
+              color: blue;
+            }
+          }
+        `,
+        { from: undefined }
+      )
+      .then(result => {
+        expect(result.css).toMatchCss(`
+          .foo {
+            color: blue;
+          }
+          @media (min-width: 400px) {
+            .mobile\\:foo {
+              color: blue;
+            }
+          }
+        `)
+        fs.unlinkSync(path.resolve('./tailwind.config.js'))
+      })
+  })
+})
diff --git a/src/index.js b/src/index.js
index 1985aee55..09530af5b 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,4 +1,5 @@
 import path from 'path'
+import fs from 'fs'
 
 import _ from 'lodash'
 import postcss from 'postcss'
@@ -8,31 +9,50 @@ import registerConfigAsDependency from './lib/registerConfigAsDependency'
 import processTailwindFeatures from './processTailwindFeatures'
 import resolveConfig from './util/resolveConfig'
 
-const plugin = postcss.plugin('tailwind', config => {
-  const plugins = []
-
-  if (!_.isUndefined(config) && !_.isObject(config)) {
-    plugins.push(registerConfigAsDependency(path.resolve(config)))
+function resolveConfigPath(filePath) {
+  if (_.isObject(filePath)) {
+    return undefined
   }
 
-  const getConfig = () => {
-    if (_.isUndefined(config)) {
-      return resolveConfig([require('../defaultConfig')()])
-    }
+  if (!_.isUndefined(filePath)) {
+    return path.resolve(filePath)
+  }
 
-    if (!_.isObject(config)) {
-      delete require.cache[require.resolve(path.resolve(config))]
-    }
+  try {
+    const defaultConfigPath = path.resolve('./tailwind.config.js')
+    fs.accessSync(defaultConfigPath)
+    return defaultConfigPath
+  } catch (err) {
+    return undefined
+  }
+}
 
-    return resolveConfig([
-      _.isObject(config) ? config : require(path.resolve(config)),
-      require('../defaultConfig')(),
-    ])
+const getConfigFunction = config => () => {
+  if (_.isUndefined(config) && !_.isObject(config)) {
+    return resolveConfig([require('../defaultConfig')()])
+  }
+
+  if (!_.isObject(config)) {
+    delete require.cache[require.resolve(config)]
+  }
+
+  return resolveConfig([
+    _.isObject(config) ? config : require(config),
+    require('../defaultConfig')(),
+  ])
+}
+
+const plugin = postcss.plugin('tailwind', config => {
+  const plugins = []
+  const resolvedConfigPath = resolveConfigPath(config)
+
+  if (!_.isUndefined(resolvedConfigPath)) {
+    plugins.push(registerConfigAsDependency(resolvedConfigPath))
   }
 
   return postcss([
     ...plugins,
-    processTailwindFeatures(getConfig),
+    processTailwindFeatures(getConfigFunction(resolvedConfigPath ? resolvedConfigPath : config)),
     perfectionist({
       cascade: true,
       colorShorthand: true,