diff --git a/index.js b/index.js
index 9dd2cc39..889cdaa7 100755
--- a/index.js
+++ b/index.js
@@ -32,7 +32,7 @@ function AtImport(options) {
 
   return {
     postcssPlugin: "postcss-import",
-    Once(styles, { result, atRule }) {
+    Once(styles, { result, atRule, postcss }) {
       const state = {
         importedFiles: {},
         hashFiles: {},
@@ -265,28 +265,30 @@ function AtImport(options) {
             if (state.hashFiles[content] && state.hashFiles[content][media])
               return
 
-            return processContent(result, content, filename, options).then(
-              importedResult => {
-                const styles = importedResult.root
-                result.messages = result.messages.concat(
-                  importedResult.messages
-                )
-
-                if (options.skipDuplicates) {
-                  const hasImport = styles.some(child => {
-                    return child.type === "atrule" && child.name === "import"
-                  })
-                  if (!hasImport) {
-                    // save hash files to skip them next time
-                    if (!state.hashFiles[content]) state.hashFiles[content] = {}
-                    state.hashFiles[content][media] = true
-                  }
+            return processContent(
+              result,
+              content,
+              filename,
+              options,
+              postcss
+            ).then(importedResult => {
+              const styles = importedResult.root
+              result.messages = result.messages.concat(importedResult.messages)
+
+              if (options.skipDuplicates) {
+                const hasImport = styles.some(child => {
+                  return child.type === "atrule" && child.name === "import"
+                })
+                if (!hasImport) {
+                  // save hash files to skip them next time
+                  if (!state.hashFiles[content]) state.hashFiles[content] = {}
+                  state.hashFiles[content][media] = true
                 }
-
-                // recursion: import @import from imported file
-                return parseStyles(result, styles, options, state, media)
               }
-            )
+
+              // recursion: import @import from imported file
+              return parseStyles(result, styles, options, state, media)
+            })
           }
         )
       }
diff --git a/lib/process-content.js b/lib/process-content.js
index 531e7745..beaa3f03 100644
--- a/lib/process-content.js
+++ b/lib/process-content.js
@@ -3,13 +3,16 @@
 // builtin tooling
 const path = require("path")
 
-// external tooling
-const postcss = require("postcss")
-
 // placeholder tooling
 let sugarss
 
-module.exports = function processContent(result, content, filename, options) {
+module.exports = function processContent(
+  result,
+  content,
+  filename,
+  options,
+  postcss
+) {
   const { plugins } = options
   const ext = path.extname(filename)
 
@@ -22,7 +25,8 @@ module.exports = function processContent(result, content, filename, options) {
         sugarss = require("sugarss")
       } catch {} // Ignore
     }
-    if (sugarss) return runPostcss(content, filename, plugins, [sugarss])
+    if (sugarss)
+      return runPostcss(postcss, content, filename, plugins, [sugarss])
   }
 
   // Syntax support:
@@ -35,10 +39,10 @@ module.exports = function processContent(result, content, filename, options) {
   // Try the default as a last resort:
   parserList.push(null)
 
-  return runPostcss(content, filename, plugins, parserList)
+  return runPostcss(postcss, content, filename, plugins, parserList)
 }
 
-function runPostcss(content, filename, plugins, parsers, index) {
+function runPostcss(postcss, content, filename, plugins, parsers, index) {
   if (!index) index = 0
   return postcss(plugins)
     .process(content, {
@@ -50,6 +54,6 @@ function runPostcss(content, filename, plugins, parsers, index) {
       index++
       // If there are no parsers left, throw it
       if (index === parsers.length) throw err
-      return runPostcss(content, filename, plugins, parsers, index)
+      return runPostcss(postcss, content, filename, plugins, parsers, index)
     })
 }