diff --git a/project/SparkBuild.scala b/project/SparkBuild.scala
index a3724a46585b6..81425b84ce3aa 100644
--- a/project/SparkBuild.scala
+++ b/project/SparkBuild.scala
@@ -354,6 +354,7 @@ object Assembly {
 object PySparkAssembly {
   import sbtassembly.Plugin._
   import AssemblyKeys._
+  import java.util.zip.{ZipOutputStream, ZipEntry}
 
   lazy val settings = Seq(
     unmanagedJars in Compile += { BuildCommons.sparkHome / "python/lib/py4j-0.8.2.1-src.zip" },
@@ -365,12 +366,7 @@ object PySparkAssembly {
 
       val zipFile = new File(BuildCommons.sparkHome , "python/lib/pyspark.zip")
       zipFile.delete()
-      def entries(f: File): List[File] =
-        f :: (if (f.isDirectory) IO.listFiles(f).toList.flatMap(entries(_)) else Nil)
-      val sources = entries(src).map { d =>
-        (d, d.getAbsolutePath.substring(src.getParent.length +1))
-      }
-      IO.zip(sources, zipFile)
+      zipRecursive(src, zipFile)
 
       val dst = new File(outDir, "pyspark")
       if (!dst.isDirectory()) {
@@ -380,6 +376,34 @@ object PySparkAssembly {
     }
   )
 
+  private def zipRecursive(source: File, destZipFile: File) = {
+    val destOutput = new ZipOutputStream(new FileOutputStream(destZipFile))
+    addFilesToZipStream("", source, destOutput)
+    destOutput.flush()
+    destOutput.close()
+  }
+
+  private def addFilesToZipStream(parent: String, source: File, output: ZipOutputStream): Unit = {
+    if (source.isDirectory()) {
+      output.putNextEntry(new ZipEntry(parent + source.getName()))
+      for (file <- source.listFiles()) {
+        addFilesToZipStream(parent + source.getName() + File.separator, file, output)
+      }
+    } else {
+      val in = new FileInputStream(source)
+      output.putNextEntry(new ZipEntry(parent + source.getName()))
+      val buf = new Array[Byte](8192)
+      var n = 0
+      while (n != -1) {
+        n = in.read(buf)
+        if (n != -1) {
+          output.write(buf, 0, n)
+        }
+      }
+      in.close()
+    }
+  }
+
   private def copy(src: File, dst: File): Seq[File] = {
     src.listFiles().flatMap { f =>
       val child = new File(dst, f.getName())