diff --git a/examples/src/main/scala/org/apache/spark/examples/streaming/StatefulNetworkWordCount.scala b/examples/src/main/scala/org/apache/spark/examples/streaming/StatefulNetworkWordCount.scala
index daa1ced63c701..a4d159bf38377 100644
--- a/examples/src/main/scala/org/apache/spark/examples/streaming/StatefulNetworkWordCount.scala
+++ b/examples/src/main/scala/org/apache/spark/examples/streaming/StatefulNetworkWordCount.scala
@@ -44,7 +44,7 @@ object StatefulNetworkWordCount {
     StreamingExamples.setStreamingLogLevels()
 
     val updateFunc = (values: Seq[Int], state: Option[Int]) => {
-      val currentCount = values.foldLeft(0)(_ + _)
+      val currentCount = values.sum
 
       val previousCount = state.getOrElse(0)
 
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala
index ff6d86c8f81ac..059ac6c2dbee2 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala
@@ -452,7 +452,7 @@ class BasicOperationsSuite extends TestSuiteBase {
 
   test("rdd cleanup - updateStateByKey") {
     val updateFunc = (values: Seq[Int], state: Option[Int]) => {
-      Some(values.foldLeft(0)(_ + _) + state.getOrElse(0))
+      Some(values.sum + state.getOrElse(0))
     }
     val stateStream = runCleanupTest(
       conf, _.map(_ -> 1).updateStateByKey(updateFunc).checkpoint(Seconds(3)))
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala
index 10ad3c9e1adc9..8511390cb1ad5 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala
@@ -70,7 +70,7 @@ class CheckpointSuite extends TestSuiteBase {
     val input = (1 to 10).map(_ => Seq("a")).toSeq
     val operation = (st: DStream[String]) => {
       val updateFunc = (values: Seq[Int], state: Option[Int]) => {
-        Some((values.foldLeft(0)(_ + _) + state.getOrElse(0)))
+        Some((values.sum + state.getOrElse(0)))
       }
       st.map(x => (x, 1))
       .updateStateByKey(updateFunc)
@@ -214,7 +214,7 @@ class CheckpointSuite extends TestSuiteBase {
     val output = (1 to 10).map(x => Seq(("a", x))).toSeq
     val operation = (st: DStream[String]) => {
       val updateFunc = (values: Seq[Int], state: Option[Int]) => {
-        Some((values.foldLeft(0)(_ + _) + state.getOrElse(0)))
+        Some((values.sum + state.getOrElse(0)))
       }
       st.map(x => (x, 1))
         .updateStateByKey(updateFunc)