diff --git a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ConstantColumnVector.java b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ConstantColumnVector.java
index 134cb05c1265c..3a5dea479cab5 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ConstantColumnVector.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/ConstantColumnVector.java
@@ -70,12 +70,17 @@ public ConstantColumnVector(int numRows, DataType type) {
 
   @Override
   public void close() {
+    stringData = null;
     byteArrayData = null;
-    for (int i = 0; i < childData.length; i++) {
-      childData[i].close();
-      childData[i] = null;
+    if (childData != null) {
+      for (int i = 0; i < childData.length; i++) {
+        if (childData[i] != null) {
+          childData[i].close();
+          childData[i] = null;
+        }
+      }
+      childData = null;
     }
-    childData = null;
     arrayData = null;
     mapData = null;
   }
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/vectorized/ConstantColumnVectorSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/vectorized/ConstantColumnVectorSuite.scala
index c8438f342d256..2bee643df4eff 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/vectorized/ConstantColumnVectorSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/vectorized/ConstantColumnVectorSuite.scala
@@ -27,7 +27,9 @@ class ConstantColumnVectorSuite extends SparkFunSuite {
   private def testVector(name: String, size: Int, dt: DataType)
     (f: ConstantColumnVector => Unit): Unit = {
     test(name) {
-      f(new ConstantColumnVector(size, dt))
+      val vector = new ConstantColumnVector(size, dt)
+      f(vector)
+      vector.close()
     }
   }