diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala
index 862f78702c4e6..26336332c05a2 100755
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala
@@ -166,7 +166,7 @@ class SqlParser extends StandardTokenParsers with PackratParsers {
         val withFilter = f.map(f => Filter(f, base)).getOrElse(base)
         val withProjection =
           g.map {g =>
-            Aggregate(assignAliases(g), assignAliases(p), withFilter)
+            Aggregate(g, assignAliases(p), withFilter)
           }.getOrElse(Project(assignAliases(p), withFilter))
         val withDistinct = d.map(_ => Distinct(withProjection)).getOrElse(withProjection)
         val withHaving = h.map(h => Filter(h, withDistinct)).getOrElse(withDistinct)
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
index fdf3a229a796e..6fb6cb8db0c8f 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
@@ -680,4 +680,9 @@ class SQLQuerySuite extends QueryTest with BeforeAndAfterAll {
       sql("SELECT CAST(TRUE AS STRING), CAST(FALSE AS STRING) FROM testData LIMIT 1"),
       ("true", "false") :: Nil)
   }
+  
+  test("SPARK-3371 Renaming a function expression with group by gives error") {
+    registerFunction("len", (s: String) => s.length)
+    checkAnswer(
+      sql("SELECT len(value) as temp FROM testData WHERE key = 1 group by len(value)"), 1)}    
 }