diff --git a/backend/src/graphql/resolver/AdminResolver.ts b/backend/src/graphql/resolver/AdminResolver.ts
index aaf3ed91f..e9ee0b55b 100644
--- a/backend/src/graphql/resolver/AdminResolver.ts
+++ b/backend/src/graphql/resolver/AdminResolver.ts
@@ -741,7 +741,7 @@ export class AdminResolver {
     }
     const queryRunner = getConnection().createQueryRunner()
     await queryRunner.connect()
-    await queryRunner.startTransaction('READ UNCOMMITTED')
+    await queryRunner.startTransaction('REPEATABLE READ')
     const contributionMessage = DbContributionMessage.create()
     try {
       const contribution = await Contribution.findOne({
diff --git a/backend/src/graphql/resolver/ContributionMessageResolver.ts b/backend/src/graphql/resolver/ContributionMessageResolver.ts
index bd2bdeec8..0b33c4722 100644
--- a/backend/src/graphql/resolver/ContributionMessageResolver.ts
+++ b/backend/src/graphql/resolver/ContributionMessageResolver.ts
@@ -23,7 +23,7 @@ export class ContributionMessageResolver {
     const user = getUser(context)
     const queryRunner = getConnection().createQueryRunner()
     await queryRunner.connect()
-    await queryRunner.startTransaction('READ COMMITTED')
+    await queryRunner.startTransaction('REPEATABLE READ')
     const contributionMessage = DbContributionMessage.create()
     try {
       const contribution = await Contribution.findOne({ id: contributionId })
diff --git a/backend/src/graphql/resolver/TransactionLinkResolver.ts b/backend/src/graphql/resolver/TransactionLinkResolver.ts
index 194126f3f..d8be2d552 100644
--- a/backend/src/graphql/resolver/TransactionLinkResolver.ts
+++ b/backend/src/graphql/resolver/TransactionLinkResolver.ts
@@ -178,7 +178,7 @@ export class TransactionLinkResolver {
       logger.info('redeem contribution link...')
       const queryRunner = getConnection().createQueryRunner()
       await queryRunner.connect()
-      await queryRunner.startTransaction('SERIALIZABLE')
+      await queryRunner.startTransaction('REPEATABLE READ')
       try {
         const contributionLink = await queryRunner.manager
           .createQueryBuilder()
diff --git a/backend/src/graphql/resolver/TransactionResolver.ts b/backend/src/graphql/resolver/TransactionResolver.ts
index dff5eccf1..7d6d3b31a 100644
--- a/backend/src/graphql/resolver/TransactionResolver.ts
+++ b/backend/src/graphql/resolver/TransactionResolver.ts
@@ -82,7 +82,7 @@ export const executeTransaction = async (
 
   const queryRunner = getConnection().createQueryRunner()
   await queryRunner.connect()
-  await queryRunner.startTransaction('READ UNCOMMITTED')
+  await queryRunner.startTransaction('REPEATABLE READ')
   logger.debug(`open Transaction to write...`)
   try {
     // transaction
diff --git a/backend/src/graphql/resolver/UserResolver.ts b/backend/src/graphql/resolver/UserResolver.ts
index 19829c95f..f589e1b35 100644
--- a/backend/src/graphql/resolver/UserResolver.ts
+++ b/backend/src/graphql/resolver/UserResolver.ts
@@ -498,7 +498,7 @@ export class UserResolver {
 
     const queryRunner = getConnection().createQueryRunner()
     await queryRunner.connect()
-    await queryRunner.startTransaction('READ UNCOMMITTED')
+    await queryRunner.startTransaction('REPEATABLE READ')
     try {
       dbUser = await queryRunner.manager.save(dbUser).catch((error) => {
         logger.error('Error while saving dbUser', error)
@@ -686,7 +686,7 @@ export class UserResolver {
 
     const queryRunner = getConnection().createQueryRunner()
     await queryRunner.connect()
-    await queryRunner.startTransaction('READ UNCOMMITTED')
+    await queryRunner.startTransaction('REPEATABLE READ')
 
     try {
       // Save user
@@ -812,7 +812,7 @@ export class UserResolver {
 
     const queryRunner = getConnection().createQueryRunner()
     await queryRunner.connect()
-    await queryRunner.startTransaction('READ UNCOMMITTED')
+    await queryRunner.startTransaction('REPEATABLE READ')
 
     try {
       await queryRunner.manager.save(userEntity).catch((error) => {