diff --git a/sql/catalyst/src/main/java/org/apache/spark/sql/execution/UnsafeExternalRowSorter.java b/sql/catalyst/src/main/java/org/apache/spark/sql/execution/UnsafeExternalRowSorter.java
index 064459e4d2568..b4b248d215315 100644
--- a/sql/catalyst/src/main/java/org/apache/spark/sql/execution/UnsafeExternalRowSorter.java
+++ b/sql/catalyst/src/main/java/org/apache/spark/sql/execution/UnsafeExternalRowSorter.java
@@ -30,9 +30,12 @@
 import org.apache.spark.TaskContext;
 import org.apache.spark.sql.AbstractScalaRowIterator;
 import org.apache.spark.sql.catalyst.InternalRow;
+import org.apache.spark.sql.catalyst.expressions.ObjectUnsafeColumnWriter;
+import org.apache.spark.sql.catalyst.expressions.UnsafeColumnWriter;
 import org.apache.spark.sql.catalyst.expressions.UnsafeRow;
 import org.apache.spark.sql.catalyst.expressions.UnsafeRowConverter;
 import org.apache.spark.sql.catalyst.util.ObjectPool;
+import org.apache.spark.sql.types.StructField;
 import org.apache.spark.sql.types.StructType;
 import org.apache.spark.unsafe.PlatformDependent;
 import org.apache.spark.util.collection.unsafe.sort.PrefixComparator;
@@ -164,6 +167,18 @@ public Iterator<InternalRow> sort(Iterator<InternalRow> inputIterator) throws IO
       return sort();
   }
 
+  /**
+   * Return true if UnsafeExternalRowSorter can sort rows with the given schema, false otherwise.
+   */
+  public static boolean supportsSchema(StructType schema) {
+    for (StructField field : schema.fields()) {
+      if (UnsafeColumnWriter.forType(field.dataType()) instanceof ObjectUnsafeColumnWriter) {
+        return false;
+      }
+    }
+    return true;
+  }
+
   private static final class RowComparator extends RecordComparator {
     private final Ordering<InternalRow> ordering;
     private final int numFields;
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/UnsafeRowConverter.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/UnsafeRowConverter.scala
index d7cc672bb0f43..245aa2829130f 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/UnsafeRowConverter.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/UnsafeRowConverter.scala
@@ -103,19 +103,6 @@ class UnsafeRowConverter(fieldTypes: Array[DataType]) {
 
 }
 
-object UnsafeRowConverter {
-  def supportsSchema(schema: StructType): Boolean = {
-    schema.forall { field =>
-      try {
-        UnsafeColumnWriter.forType(field.dataType)
-        true
-      } catch {
-        case e: UnsupportedOperationException => false
-      }
-    }
-  }
-}
-
 /**
  * Function for writing a column into an UnsafeRow.
  */
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala
index 07206da424d27..826752c26bc35 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala
@@ -298,7 +298,7 @@ private[sql] abstract class SparkStrategies extends QueryPlanner[SparkPlan] {
      *               if necessary.
      */
     def getSortOperator(sortExprs: Seq[SortOrder], global: Boolean, child: SparkPlan): SparkPlan = {
-      if (sqlContext.conf.unsafeEnabled && UnsafeRowConverter.supportsSchema(child.schema)) {
+      if (sqlContext.conf.unsafeEnabled && UnsafeExternalSort.supportsSchema(child.schema)) {
         execution.UnsafeExternalSort(sortExprs, global, child)
       } else if (sqlContext.conf.externalSortEnabled) {
         execution.ExternalSort(sortExprs, global, child)
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/basicOperators.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/basicOperators.scala
index 4d58983d219da..80e9b1b0867de 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/basicOperators.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/basicOperators.scala
@@ -286,6 +286,16 @@ case class UnsafeExternalSort(
   override def outputOrdering: Seq[SortOrder] = sortOrder
 }
 
+@DeveloperApi
+object UnsafeExternalSort {
+  /**
+   * Return true if UnsafeExternalSort can sort rows with the given schema, false otherwise.
+   */
+  def supportsSchema(schema: StructType): Boolean = {
+    UnsafeExternalRowSorter.supportsSchema(schema)
+  }
+}
+
 
 /**
  * :: DeveloperApi ::