diff --git a/core/src/test/scala/org/apache/spark/ContextCleanerSuite.scala b/core/src/test/scala/org/apache/spark/ContextCleanerSuite.scala
index 4bc4346c0a288..226400945953b 100644
--- a/core/src/test/scala/org/apache/spark/ContextCleanerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/ContextCleanerSuite.scala
@@ -21,7 +21,6 @@ import java.lang.ref.WeakReference
 
 import scala.collection.mutable.{HashSet, SynchronizedSet}
 import scala.language.existentials
-import scala.language.postfixOps
 import scala.util.Random
 
 import org.scalatest.{BeforeAndAfter, FunSuite}
@@ -47,6 +46,8 @@ import org.apache.spark.storage.ShuffleIndexBlockId
 abstract class ContextCleanerSuiteBase(val shuffleManager: Class[_] = classOf[HashShuffleManager])
   extends FunSuite with BeforeAndAfter with LocalSparkContext
 {
+  import scala.language.postfixOps
+
   implicit val defaultTimeout = timeout(10000 millis)
   val conf = new SparkConf()
     .setMaster("local[2]")
diff --git a/core/src/test/scala/org/apache/spark/rdd/AsyncRDDActionsSuite.scala b/core/src/test/scala/org/apache/spark/rdd/AsyncRDDActionsSuite.scala
index 28197657e9bad..e4b6d1c18b4f6 100644
--- a/core/src/test/scala/org/apache/spark/rdd/AsyncRDDActionsSuite.scala
+++ b/core/src/test/scala/org/apache/spark/rdd/AsyncRDDActionsSuite.scala
@@ -22,7 +22,6 @@ import java.util.concurrent.Semaphore
 import scala.concurrent.{Await, TimeoutException}
 import scala.concurrent.duration.Duration
 import scala.concurrent.ExecutionContext.Implicits.global
-import scala.language.postfixOps
 
 import org.scalatest.{BeforeAndAfterAll, FunSuite}
 import org.scalatest.concurrent.Timeouts
@@ -32,6 +31,7 @@ import org.apache.spark.SparkContext._
 import org.apache.spark.{SparkContext, SparkException, LocalSparkContext}
 
 class AsyncRDDActionsSuite extends FunSuite with BeforeAndAfterAll with Timeouts {
+  import scala.language.postfixOps
 
   @transient private var sc: SparkContext = _
 
diff --git a/core/src/test/scala/org/apache/spark/ui/UISuite.scala b/core/src/test/scala/org/apache/spark/ui/UISuite.scala
index 038746d2eda4b..2a77642f6f844 100644
--- a/core/src/test/scala/org/apache/spark/ui/UISuite.scala
+++ b/core/src/test/scala/org/apache/spark/ui/UISuite.scala
@@ -21,7 +21,6 @@ import java.net.ServerSocket
 import javax.servlet.http.HttpServletRequest
 
 import scala.io.Source
-import scala.language.postfixOps
 import scala.util.{Failure, Success, Try}
 
 import org.eclipse.jetty.server.Server
@@ -35,6 +34,7 @@ import org.apache.spark.LocalSparkContext._
 import scala.xml.Node
 
 class UISuite extends FunSuite {
+  import scala.language.postfixOps
 
   ignore("basic ui visibility") {
     withSpark(new SparkContext("local", "test")) { sc =>
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/NetworkReceiverSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/NetworkReceiverSuite.scala
index f4e11f975de94..cf52475778c9e 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/NetworkReceiverSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/NetworkReceiverSuite.scala
@@ -20,7 +20,6 @@ package org.apache.spark.streaming
 import java.nio.ByteBuffer
 
 import scala.collection.mutable.ArrayBuffer
-import scala.language.postfixOps
 
 import org.apache.spark.SparkConf
 import org.apache.spark.storage.{StorageLevel, StreamBlockId}
@@ -32,6 +31,7 @@ import org.scalatest.time.SpanSugar._
 
 /** Testsuite for testing the network receiver behavior */
 class NetworkReceiverSuite extends FunSuite with Timeouts {
+  import scala.language.postfixOps
 
   test("network receiver life cycle") {
 
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/StreamingListenerSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/StreamingListenerSuite.scala
index 2861f5335ae36..cc8ae3d0c5adf 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/StreamingListenerSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/StreamingListenerSuite.scala
@@ -20,7 +20,6 @@ package org.apache.spark.streaming
 import scala.collection.mutable.ArrayBuffer
 import scala.concurrent.Future
 import scala.concurrent.ExecutionContext.Implicits.global
-import scala.language.postfixOps
 
 import org.apache.spark.storage.StorageLevel
 import org.apache.spark.streaming.dstream.DStream
@@ -33,6 +32,7 @@ import org.scalatest.time.SpanSugar._
 import org.apache.spark.Logging
 
 class StreamingListenerSuite extends TestSuiteBase with Matchers {
+  import scala.language.postfixOps
 
   val input = (1 to 4).map(Seq(_)).toSeq
   val operation = (d: DStream[Int]) => d.map(x => x)
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/UISuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/UISuite.scala
index 2a0db7564915d..92e6bb71336f0 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/UISuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/UISuite.scala
@@ -18,13 +18,13 @@
 package org.apache.spark.streaming
 
 import scala.io.Source
-import scala.language.postfixOps
 
 import org.scalatest.FunSuite
 import org.scalatest.concurrent.Eventually._
 import org.scalatest.time.SpanSugar._
 
 class UISuite extends FunSuite {
+  import scala.language.postfixOps
 
   // Ignored: See SPARK-1530
   ignore("streaming tab in spark UI") {