diff --git a/core/src/main/scala/org/apache/spark/util/Utils.scala b/core/src/main/scala/org/apache/spark/util/Utils.scala
index 13d9dbdd9af2d..388681b048c7c 100644
--- a/core/src/main/scala/org/apache/spark/util/Utils.scala
+++ b/core/src/main/scala/org/apache/spark/util/Utils.scala
@@ -26,7 +26,7 @@ import java.util.concurrent.{ConcurrentHashMap, Executors, ThreadPoolExecutor}
 import scala.collection.JavaConversions._
 import scala.collection.Map
 import scala.collection.mutable.ArrayBuffer
-import scala.io.Source
+import scala.io.{Codec, Source}
 import scala.reflect.ClassTag
 
 import com.google.common.io.Files
@@ -644,6 +644,11 @@ private[spark] object Utils extends Logging {
     for ((key, value) <- extraEnvironment) {
       environment.put(key, value)
     }
+    implicit val codec = if (System.getProperty("os.name").startsWith("Windows")) {
+      Codec.ISO8859
+    } else {
+      Codec.UTF8
+    }
     val process = builder.start()
     new Thread("read stderr for " + command(0)) {
       override def run() {