diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/types/StructType.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/types/StructType.scala
index 0205c13aa986..c1310308c44b 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/types/StructType.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/types/StructType.scala
@@ -18,6 +18,7 @@
 package org.apache.spark.sql.types
 
 import scala.collection.mutable.ArrayBuffer
+import scala.util.control.NonFatal
 import scala.util.Try
 
 import org.json4s.JsonDSL._
@@ -468,10 +469,16 @@ object StructType extends AbstractDataType {
         leftFields.foreach {
           case leftField @ StructField(leftName, leftType, leftNullable, _) =>
             rightMapped.get(leftName)
-              .map { case rightField @ StructField(_, rightType, rightNullable, _) =>
-                leftField.copy(
-                  dataType = merge(leftType, rightType),
-                  nullable = leftNullable || rightNullable)
+              .map { case rightField @ StructField(rightName, rightType, rightNullable, _) =>
+                try {
+                  leftField.copy(
+                    dataType = merge(leftType, rightType),
+                    nullable = leftNullable || rightNullable)
+                } catch {
+                  case NonFatal(e) =>
+                    throw new SparkException(s"Failed to merge fields '$leftName' and " +
+                      s"'$rightName'. " + e.getMessage)
+                }
               }
               .orElse {
                 optionalMeta.putBoolean(metadataKeyForOptionalField, value = true)
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/types/DataTypeSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/types/DataTypeSuite.scala
index b8ab9a9963de..efb104299f0e 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/types/DataTypeSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/types/DataTypeSuite.scala
@@ -189,9 +189,11 @@ class DataTypeSuite extends SparkFunSuite {
     val right = StructType(
       StructField("b", LongType) :: Nil)
 
-    intercept[SparkException] {
+    val message = intercept[SparkException] {
       left.merge(right)
-    }
+    }.getMessage
+    assert(message.equals("Failed to merge fields 'b' and 'b'. " +
+      "Failed to merge incompatible data types FloatType and LongType"))
   }
 
   test("existsRecursively") {