diff --git a/study/src/test/java/transaction/stage1/Stage1Test.java b/study/src/test/java/transaction/stage1/Stage1Test.java
index d73e4ee476..eb20b2176f 100644
--- a/study/src/test/java/transaction/stage1/Stage1Test.java
+++ b/study/src/test/java/transaction/stage1/Stage1Test.java
@@ -80,7 +80,7 @@ void dirtyReading() throws SQLException {
             final var subConnection = dataSource.getConnection();
 
             // 적절한 격리 레벨을 찾는다.
-            final int isolationLevel = Connection.TRANSACTION_SERIALIZABLE;
+            final int isolationLevel = Connection.TRANSACTION_READ_COMMITTED;
 
             // 트랜잭션 격리 레벨을 설정한다.
             subConnection.setTransactionIsolation(isolationLevel);
@@ -129,7 +129,7 @@ void noneRepeatable() throws SQLException {
         connection.setAutoCommit(false);
 
         // 적절한 격리 레벨을 찾는다.
-        final int isolationLevel = Connection.TRANSACTION_SERIALIZABLE;
+        final int isolationLevel = Connection.TRANSACTION_REPEATABLE_READ;
 
         // 트랜잭션 격리 레벨을 설정한다.
         connection.setTransactionIsolation(isolationLevel);