diff --git a/__tests__/mergeConfigWithDefaults.test.js b/__tests__/mergeConfigWithDefaults.test.js
index c6474794c..5b787bf1b 100644
--- a/__tests__/mergeConfigWithDefaults.test.js
+++ b/__tests__/mergeConfigWithDefaults.test.js
@@ -80,6 +80,33 @@ test('setting modules to "all" creates all variants for all modules', () => {
   })
 })
 
+test('setting modules to an array of variants applies those variants to all modules', () => {
+  const userConfig = {
+    modules: ['responsive', 'focus', 'hover', 'custom-variant'],
+    options: {},
+  }
+
+  const defaultConfig = {
+    modules: {
+      flexbox: ['responsive'],
+      textAlign: ['hover'],
+      textColors: ['focus'],
+    },
+    options: {},
+  }
+
+  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'],
+    },
+    options: {},
+  })
+})
+
 test('user options are merged with default options', () => {
   const userConfig = {
     modules: {},
diff --git a/src/util/mergeConfigWithDefaults.js b/src/util/mergeConfigWithDefaults.js
index 8e5af64f4..44c996538 100644
--- a/src/util/mergeConfigWithDefaults.js
+++ b/src/util/mergeConfigWithDefaults.js
@@ -1,6 +1,10 @@
 import _ from 'lodash'
 
 function mergeModules(userModules, defaultModules) {
+  if (_.isArray(userModules)) {
+    return _.mapValues(defaultModules, () => userModules)
+  }
+
   if (userModules === 'all') {
     return _.mapValues(defaultModules, () => [
       'responsive',