diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/NestedColumnAliasing.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/NestedColumnAliasing.scala
index 8de2663a98094..cd4070b391234 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/NestedColumnAliasing.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/NestedColumnAliasing.scala
@@ -185,9 +185,23 @@ object NestedColumnAliasing {
       plan: LogicalPlan,
       nestedFieldToAlias: Map[Expression, Alias],
       attrToAliases: AttributeMap[Seq[Alias]]): LogicalPlan = {
-    plan.withNewChildren(plan.children.map { plan =>
-      Project(plan.output.flatMap(a => attrToAliases.getOrElse(a, Seq(a))), plan)
-    }).transformExpressions {
+    // withNewChildren is dangerous for Generate;
+    // one has to adjust unrequiredChildIndex accordingly in this case
+    val withNewChildren = plan match {
+      case g: Generate =>
+        val unrequiredSet = g.unrequiredChildIndex.toSet
+        val flagRes = g.child.output.zipWithIndex.flatMap( t =>
+          attrToAliases.getOrElse(t._1, Seq(t._1)).map( e => ( e, unrequiredSet.contains(t._2) ) )
+        )
+        val unrequiredChildIndex = flagRes.map(_._2).zipWithIndex.filter(t => t._1).map(_._2)
+        g.copy(
+          child = Project(flagRes.map(_._1), g.child),
+          unrequiredChildIndex = unrequiredChildIndex
+        )
+      case _ => plan.withNewChildren(plan.children.map { plan =>
+        Project(plan.output.flatMap(a => attrToAliases.getOrElse(a, Seq(a))), plan)})
+    }
+    withNewChildren.transformExpressions {
       case f: ExtractValue if nestedFieldToAlias.contains(f.canonicalized) =>
         nestedFieldToAlias(f.canonicalized).toAttribute
     }