diff --git a/core/src/test/scala/org/apache/spark/internal/config/ConfigEntrySuite.scala b/core/src/test/scala/org/apache/spark/internal/config/ConfigEntrySuite.scala
index 6bd63fa5ffa4..1c9a9a120345 100644
--- a/core/src/test/scala/org/apache/spark/internal/config/ConfigEntrySuite.scala
+++ b/core/src/test/scala/org/apache/spark/internal/config/ConfigEntrySuite.scala
@@ -94,6 +94,8 @@ class ConfigEntrySuite extends SparkFunSuite {
     assert(conf.get(bytes) === 1024L)
     conf.set(bytes.key, "1k")
     assert(conf.get(bytes) === 1L)
+    conf.set(bytes.key, "2048")
+    assert(conf.get(bytes) === 2048)
   }
 
   test("conf entry: regex") {
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
index 9f71ecb756a6..4110ae54ee6c 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
@@ -1415,8 +1415,8 @@ object SQLConf {
       " bigger files (which is scheduled first). This configuration is effective only when using" +
       " file-based sources such as Parquet, JSON and ORC.")
     .version("2.0.0")
-    .longConf
-    .createWithDefault(4 * 1024 * 1024)
+    .bytesConf(ByteUnit.BYTE)
+    .createWithDefaultString("4MB")
 
   val FILES_MIN_PARTITION_NUM = buildConf("spark.sql.files.minPartitionNum")
     .doc("The suggested (not guaranteed) minimum number of split file partitions. " +