diff --git a/core/src/main/scala/org/apache/spark/api/java/JavaUtils.scala b/core/src/main/scala/org/apache/spark/api/java/JavaUtils.scala
index abf873a7f8546..71b26737b8c02 100644
--- a/core/src/main/scala/org/apache/spark/api/java/JavaUtils.scala
+++ b/core/src/main/scala/org/apache/spark/api/java/JavaUtils.scala
@@ -80,7 +80,7 @@ private[spark] object JavaUtils {
           prev match {
             case Some(k) =>
               underlying match {
-                case mm: mutable.Map[_, _] =>
+                case mm: mutable.Map[A, _] =>
                   mm remove k
                   prev = None
                 case _ =>