diff --git a/sql/core/src/main/scala/org/apache/spark/sql/SQLConf.scala b/sql/core/src/main/scala/org/apache/spark/sql/SQLConf.scala
index 61a7b9935af0ba39daad7fc04763008c3a3eacf0..a601c87fc930eb01b927cbb54f6db35962623a3e 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/SQLConf.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/SQLConf.scala
@@ -430,7 +430,7 @@ private[spark] object SQLConf {
 
   val PARTITION_MAX_FILES =
     intConf("spark.sql.sources.maxConcurrentWrites",
-      defaultValue = Some(5),
+      defaultValue = Some(1),
       doc = "The maximum number of concurrent files to open before falling back on sorting when " +
             "writing out files using dynamic partitioning.")