diff --git a/__tests__/customConfig.test.js b/__tests__/customConfig.test.js
index b757dff25..8048673c3 100644
--- a/__tests__/customConfig.test.js
+++ b/__tests__/customConfig.test.js
@@ -1,7 +1,21 @@
+import fs from 'fs'
 import path from 'path'
+import rimraf from 'rimraf'
 import postcss from 'postcss'
 import tailwind from '../src/index'
 
+function inTempDirectory(callback) {
+  return new Promise(resolve => {
+    rimraf.sync('./__tmp')
+    fs.mkdirSync(path.resolve('./__tmp'))
+    process.chdir(path.resolve('./__tmp'))
+    callback().then(() => {
+      process.chdir(path.resolve('../'))
+      rimraf('./__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 +39,6 @@ test('it uses the values from the custom config file', () => {
           }
         }
       `
-
       expect(result.css).toMatchCss(expected)
     })
 })
@@ -65,3 +78,42 @@ 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;
+            }
+          }
+        `)
+      })
+  })
+})
diff --git a/package.json b/package.json
index a42b25626..a04489ac6 100644
--- a/package.json
+++ b/package.json
@@ -38,7 +38,7 @@
     "eslint-plugin-prettier": "^2.3.1",
     "jest": "^23.6.0",
     "prettier": "^1.7.4",
-    "rimraf": "^2.6.1"
+    "rimraf": "^2.6.3"
   },
   "dependencies": {
     "autoprefixer": "^9.4.5",
diff --git a/src/index.js b/src/index.js
index 1985aee55..b1bbf50f6 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 || config)),
     perfectionist({
       cascade: true,
       colorShorthand: true,
diff --git a/yarn.lock b/yarn.lock
index 0e8157d76..c2a64be6c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2174,6 +2174,18 @@ glob@^7.0.3, glob@^7.0.5, glob@^7.1.1, glob@^7.1.2:
     once "^1.3.0"
     path-is-absolute "^1.0.0"
 
+glob@^7.1.3:
+  version "7.1.3"
+  resolved "https://registry.yarnpkg.com/glob/-/glob-7.1.3.tgz#3960832d3f1574108342dafd3a67b332c0969df1"
+  integrity sha512-vcfuiIxogLV4DlGBHIUOwI0IbrJ8HWPc4MU7HzviGeNho/UJDfi6B5p3sHeWIQ0KGIU0Jpxi5ZHxemQfLkkAwQ==
+  dependencies:
+    fs.realpath "^1.0.0"
+    inflight "^1.0.4"
+    inherits "2"
+    minimatch "^3.0.4"
+    once "^1.3.0"
+    path-is-absolute "^1.0.0"
+
 globals@^11.0.1:
   version "11.5.0"
   resolved "https://registry.yarnpkg.com/globals/-/globals-11.5.0.tgz#6bc840de6771173b191f13d3a9c94d441ee92642"
@@ -4381,6 +4393,13 @@ rimraf@^2.2.8, rimraf@^2.5.4, rimraf@^2.6.1:
   dependencies:
     glob "^7.0.5"
 
+rimraf@^2.6.3:
+  version "2.6.3"
+  resolved "https://registry.yarnpkg.com/rimraf/-/rimraf-2.6.3.tgz#b2d104fe0d8fb27cf9e0a1cda8262dd3833c6cab"
+  integrity sha512-mwqeW5XsA2qAejG46gYdENaxXjx9onRNCfn7L0duuP4hCuTIi/QO7PDK07KJfp1d+izWPrzEJDcSqBa0OZQriA==
+  dependencies:
+    glob "^7.1.3"
+
 rsvp@^3.3.3:
   version "3.6.2"
   resolved "https://registry.yarnpkg.com/rsvp/-/rsvp-3.6.2.tgz#2e96491599a96cde1b515d5674a8f7a91452926a"