diff --git a/jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostClassifier.scala b/jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostClassifier.scala
index 6b48a50f8..b35f5da34 100644
--- a/jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostClassifier.scala
+++ b/jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostClassifier.scala
@@ -415,7 +415,9 @@ class XGBoostClassificationModel private[ml](
     var numColsOutput = 0
 
     val rawPredictionUDF = udf { rawPrediction: mutable.WrappedArray[Float] =>
-      Vectors.dense(rawPrediction.map(_.toDouble).toArray)
+      val raw = rawPrediction.map(_.toDouble).toArray
+      val rawPredictions = if (numClasses == 2) Array(-raw(0), raw(0)) else raw
+      Vectors.dense(rawPredictions)
     }
 
     val probabilityUDF = udf { probability: mutable.WrappedArray[Float] =>
diff --git a/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostClassifierSuite.scala b/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostClassifierSuite.scala
index 8b7bdb448..7645d2c89 100644
--- a/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostClassifierSuite.scala
+++ b/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostClassifierSuite.scala
@@ -60,10 +60,11 @@ class XGBoostClassifierSuite extends FunSuite with PerTest {
       collect().map(row => (row.getAs[Int]("id"), row.getAs[DenseVector]("rawPrediction"))).toMap
 
     assert(testDF.count() === prediction4.size)
+    // the vector length in rawPrediction column is 2 since we have to fit to the evaluator in Spark
     for (i <- prediction3.indices) {
-      assert(prediction3(i).length === prediction4(i).values.length)
+      assert(prediction3(i).length === prediction4(i).values.length - 1)
       for (j <- prediction3(i).indices) {
-        assert(prediction3(i)(j) === prediction4(i)(j))
+        assert(prediction3(i)(j) === prediction4(i)(j + 1))
       }
     }