diff --git a/__tests__/mergeConfigWithDefaults.test.js b/__tests__/mergeConfigWithDefaults.test.js
index e9bf3f1d1..135681356 100644
--- a/__tests__/mergeConfigWithDefaults.test.js
+++ b/__tests__/mergeConfigWithDefaults.test.js
@@ -1,28 +1,23 @@
 import mergeConfigWithDefaults from '../src/util/mergeConfigWithDefaults'
 
-test('user top-level keys override default top-level keys except modules', () => {
+test('user top-level keys override default top-level keys', () => {
   const userConfig = {
-    modules: {},
     prefix: 'tw-',
     important: true,
   }
 
   const defaultConfig = {
-    modules: {
-      flexbox: ['responsive'],
-    },
     prefix: '-',
     important: false,
+    separator: ':',
   }
 
   const result = mergeConfigWithDefaults(userConfig, defaultConfig)
 
   expect(result).toEqual({
-    modules: {
-      flexbox: ['responsive'],
-    },
     prefix: 'tw-',
     important: true,
+    separator: ':',
   })
 })
 
@@ -50,73 +45,3 @@ test('missing top level keys are pulled from the default config', () => {
     modules: {},
   })
 })
-
-test('user modules are merged with default modules', () => {
-  const userConfig = {
-    modules: { flexbox: false },
-  }
-
-  const defaultConfig = {
-    modules: {
-      flexbox: ['responsive'],
-      textAlign: ['responsive'],
-    },
-  }
-
-  const result = mergeConfigWithDefaults(userConfig, defaultConfig)
-
-  expect(result).toEqual({
-    modules: {
-      flexbox: false,
-      textAlign: ['responsive'],
-    },
-  })
-})
-
-test('setting modules to "all" creates all variants for all modules', () => {
-  const userConfig = {
-    modules: 'all',
-  }
-
-  const defaultConfig = {
-    modules: {
-      flexbox: ['responsive'],
-      textAlign: ['hover'],
-      textColors: ['focus'],
-    },
-  }
-
-  const result = mergeConfigWithDefaults(userConfig, defaultConfig)
-
-  expect(result).toEqual({
-    modules: {
-      flexbox: ['responsive', 'group-hover', 'hover', 'focus-within', 'focus', 'active'],
-      textAlign: ['responsive', 'group-hover', 'hover', 'focus-within', 'focus', 'active'],
-      textColors: ['responsive', 'group-hover', 'hover', 'focus-within', 'focus', 'active'],
-    },
-  })
-})
-
-test('setting modules to an array of variants applies those variants to all modules', () => {
-  const userConfig = {
-    modules: ['responsive', 'focus', 'hover', 'custom-variant'],
-  }
-
-  const defaultConfig = {
-    modules: {
-      flexbox: ['responsive'],
-      textAlign: ['hover'],
-      textColors: ['focus'],
-    },
-  }
-
-  const result = mergeConfigWithDefaults(userConfig, defaultConfig)
-
-  expect(result).toEqual({
-    modules: {
-      flexbox: ['responsive', 'focus', 'hover', 'custom-variant'],
-      textAlign: ['responsive', 'focus', 'hover', 'custom-variant'],
-      textColors: ['responsive', 'focus', 'hover', 'custom-variant'],
-    },
-  })
-})
diff --git a/src/util/mergeConfigWithDefaults.js b/src/util/mergeConfigWithDefaults.js
index 561f1f347..4be7a1f99 100644
--- a/src/util/mergeConfigWithDefaults.js
+++ b/src/util/mergeConfigWithDefaults.js
@@ -1,26 +1,5 @@
 import _ from 'lodash'
 
-function mergeModules(userModules, defaultModules) {
-  if (_.isArray(userModules)) {
-    return _.mapValues(defaultModules, () => userModules)
-  }
-
-  if (userModules === 'all') {
-    return _.mapValues(defaultModules, () => [
-      'responsive',
-      'group-hover',
-      'hover',
-      'focus-within',
-      'focus',
-      'active',
-    ])
-  }
-
-  return _.defaults(userModules, defaultModules)
-}
-
 export default function(userConfig, defaultConfig) {
-  _.defaults(userConfig, defaultConfig)
-  userConfig.modules = mergeModules(userConfig.modules, defaultConfig.modules)
-  return userConfig
+  return _.defaults(userConfig, defaultConfig)
 }