diff --git a/src/add.ts b/src/add.ts
index 6dc924d..76b32ac 100644
--- a/src/add.ts
+++ b/src/add.ts
@@ -93,7 +93,9 @@ export const addPackages = async (
     }
     const destYalcCopyDir = join(workingDir, values.yalcPackagesFolder, name)
 
-    await copyDirSafe(storedPackageDir, destYalcCopyDir)
+    const storeCache = {}
+
+    await copyDirSafe(storedPackageDir, destYalcCopyDir, storeCache)
 
     let replacedVersion = ''
     if (doPure) {
@@ -121,7 +123,7 @@ export const addPackages = async (
       if (options.link || options.linkDep) {
         ensureSymlinkSync(destYalcCopyDir, destModulesDir, 'junction')
       } else {
-        await copyDirSafe(storedPackageDir, destModulesDir)
+        await copyDirSafe(storedPackageDir, destModulesDir, storeCache)
       }
 
       if (!options.link) {
diff --git a/src/sync-dir.ts b/src/sync-dir.ts
index 6a10e1b..3550720 100644
--- a/src/sync-dir.ts
+++ b/src/sync-dir.ts
@@ -4,6 +4,15 @@ import { resolve } from 'path'
 import * as fs from 'fs-extra'
 import { getFileHash } from './copy'
 
+type Cache = {
+  [dir: string]: {
+    glob: string[]
+    files: {
+      [file: string]: { stat: fs.Stats; hash: string }
+    }
+  }
+}
+
 const NODE_MAJOR_VERSION = parseInt(
   (<any>process).versions.node.split('.').shift(),
   10
@@ -17,15 +26,6 @@ if (NODE_MAJOR_VERSION >= 8 && NODE_MAJOR_VERSION < 10) {
 
 const globP = util.promisify(glob)
 
-const cache: {
-  [dir: string]: {
-    glob: string[]
-    files: {
-      [file: string]: { stat: fs.Stats; hash: string }
-    }
-  }
-} = {}
-
 const makeListMap = (list: string[]) => {
   return list.reduce(
     (map, item) => {
@@ -43,7 +43,11 @@ const theSameStats = (srcStat: fs.Stats, destStat: fs.Stats) => {
   )
 }
 
-export const copyDirSafe = async (srcDir: string, destDir: string) => {
+export const copyDirSafe = async (
+  srcDir: string,
+  destDir: string,
+  cache: Cache = {}
+) => {
   const ignore = '**/node_modules/**'
   const dot = true
   const nodir = true