diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/CatalystTypeConverters.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/CatalystTypeConverters.scala
index 8d0c64eae4774..966623ed017ba 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/CatalystTypeConverters.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/CatalystTypeConverters.scala
@@ -329,7 +329,10 @@ object CatalystTypeConverters {
         null
       }
     }
-    override def toScala(catalystValue: Decimal): JavaBigDecimal = catalystValue.toJavaBigDecimal
+    override def toScala(catalystValue: Decimal): JavaBigDecimal = {
+      if (catalystValue == null) null
+      else catalystValue.toJavaBigDecimal
+    }
     override def toScalaImpl(row: InternalRow, column: Int): JavaBigDecimal =
       row.getDecimal(column, dataType.precision, dataType.scale).toJavaBigDecimal
   }
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/CatalystTypeConvertersSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/CatalystTypeConvertersSuite.scala
index df0f04563edcf..03bb102c67fe7 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/CatalystTypeConvertersSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/CatalystTypeConvertersSuite.scala
@@ -32,7 +32,9 @@ class CatalystTypeConvertersSuite extends SparkFunSuite {
     IntegerType,
     LongType,
     FloatType,
-    DoubleType)
+    DoubleType,
+    DecimalType.SYSTEM_DEFAULT,
+    DecimalType.USER_DEFAULT)
 
   test("null handling in rows") {
     val schema = StructType(simpleTypes.map(t => StructField(t.getClass.getName, t)))