diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/HazelcastSessionConfiguration.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/HazelcastSessionConfiguration.java
index ed568e8b83..4a3432467c 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/HazelcastSessionConfiguration.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/HazelcastSessionConfiguration.java
@@ -27,6 +27,8 @@ import org.springframework.boot.context.properties.PropertyMapper;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
+import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
 import org.springframework.session.SessionRepository;
 import org.springframework.session.config.SessionRepositoryCustomizer;
 import org.springframework.session.hazelcast.HazelcastIndexedSessionRepository;
@@ -49,6 +51,7 @@ import org.springframework.session.hazelcast.config.annotation.web.http.Hazelcas
 class HazelcastSessionConfiguration {
 
 	@Bean
+	@Order(Ordered.HIGHEST_PRECEDENCE)
 	SessionRepositoryCustomizer<HazelcastIndexedSessionRepository> springBootSessionRepositoryCustomizer(
 			SessionProperties sessionProperties, HazelcastSessionProperties hazelcastSessionProperties,
 			ServerProperties serverProperties) {
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/MongoSessionConfiguration.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/MongoSessionConfiguration.java
index 97d7c6fa9a..97910540f9 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/MongoSessionConfiguration.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/MongoSessionConfiguration.java
@@ -25,6 +25,8 @@ import org.springframework.boot.context.properties.PropertyMapper;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
+import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
 import org.springframework.data.mongodb.core.MongoOperations;
 import org.springframework.session.SessionRepository;
 import org.springframework.session.config.SessionRepositoryCustomizer;
@@ -47,6 +49,7 @@ import org.springframework.session.data.mongo.config.annotation.web.http.MongoHt
 class MongoSessionConfiguration {
 
 	@Bean
+	@Order(Ordered.HIGHEST_PRECEDENCE)
 	SessionRepositoryCustomizer<MongoIndexedSessionRepository> springBootSessionRepositoryCustomizer(
 			SessionProperties sessionProperties, MongoSessionProperties mongoSessionProperties,
 			ServerProperties serverProperties) {
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/RedisSessionConfiguration.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/RedisSessionConfiguration.java
index fefd83f552..71faf77987 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/RedisSessionConfiguration.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/RedisSessionConfiguration.java
@@ -27,6 +27,8 @@ import org.springframework.boot.context.properties.source.InvalidConfigurationPr
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
+import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
 import org.springframework.data.redis.connection.RedisConnectionFactory;
 import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.session.SessionRepository;
@@ -61,6 +63,7 @@ class RedisSessionConfiguration {
 	static class DefaultRedisSessionConfiguration {
 
 		@Bean
+		@Order(Ordered.HIGHEST_PRECEDENCE)
 		SessionRepositoryCustomizer<RedisSessionRepository> springBootSessionRepositoryCustomizer(
 				SessionProperties sessionProperties, RedisSessionProperties redisSessionProperties,
 				ServerProperties serverProperties) {
@@ -98,6 +101,7 @@ class RedisSessionConfiguration {
 		}
 
 		@Bean
+		@Order(Ordered.HIGHEST_PRECEDENCE)
 		SessionRepositoryCustomizer<RedisIndexedSessionRepository> springBootSessionRepositoryCustomizer(
 				SessionProperties sessionProperties, RedisSessionProperties redisSessionProperties,
 				ServerProperties serverProperties) {
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationHazelcastTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationHazelcastTests.java
index 556a38f8cc..6ee21e1606 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationHazelcastTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationHazelcastTests.java
@@ -31,6 +31,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.session.FlushMode;
 import org.springframework.session.SaveMode;
+import org.springframework.session.config.SessionRepositoryCustomizer;
 import org.springframework.session.data.mongo.MongoIndexedSessionRepository;
 import org.springframework.session.data.redis.RedisIndexedSessionRepository;
 import org.springframework.session.hazelcast.HazelcastIndexedSessionRepository;
@@ -112,6 +113,17 @@ class SessionAutoConfigurationHazelcastTests extends AbstractSessionAutoConfigur
 		});
 	}
 
+	@Test
+	void whenTheUserDefinesTheirOwnSessionRepositoryCustomizerThenDefaultConfigurationIsOverwritten() {
+		this.contextRunner.withUserConfiguration(CustomizerConfiguration.class)
+			.withPropertyValues("spring.session.hazelcast.save-mode=on-get-attribute")
+			.run((context) -> {
+				HazelcastIndexedSessionRepository repository = validateSessionRepository(context,
+						HazelcastIndexedSessionRepository.class);
+				assertThat(repository).hasFieldOrPropertyWithValue("saveMode", SaveMode.ALWAYS);
+			});
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class HazelcastConfiguration {
 
@@ -127,4 +139,14 @@ class SessionAutoConfigurationHazelcastTests extends AbstractSessionAutoConfigur
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class CustomizerConfiguration {
+
+		@Bean
+		SessionRepositoryCustomizer<HazelcastIndexedSessionRepository> sessionRepositoryCustomizer() {
+			return (repository) -> repository.setSaveMode(SaveMode.ALWAYS);
+		}
+
+	}
+
 }
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationMongoTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationMongoTests.java
index 6af94eb574..ec221f78d6 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationMongoTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationMongoTests.java
@@ -32,6 +32,9 @@ import org.springframework.boot.test.context.assertj.AssertableWebApplicationCon
 import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
 import org.springframework.boot.testsupport.testcontainers.DockerImageNames;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.session.config.SessionRepositoryCustomizer;
 import org.springframework.session.data.mongo.MongoIndexedSessionRepository;
 import org.springframework.session.data.redis.RedisIndexedSessionRepository;
 import org.springframework.session.hazelcast.HazelcastIndexedSessionRepository;
@@ -75,6 +78,13 @@ class SessionAutoConfigurationMongoTests extends AbstractSessionAutoConfiguratio
 			.run(validateSpringSessionUsesMongo("foo"));
 	}
 
+	@Test
+	void whenTheUserDefinesTheirOwnSessionRepositoryCustomizerThenDefaultConfigurationIsOverwritten() {
+		this.contextRunner.withUserConfiguration(CustomizerConfiguration.class)
+			.withPropertyValues("spring.session.mongodb.collection-name=foo")
+			.run(validateSpringSessionUsesMongo("customized"));
+	}
+
 	private ContextConsumer<AssertableWebApplicationContext> validateSpringSessionUsesMongo(String collectionName) {
 		return validateSpringSessionUsesMongo(collectionName,
 				new ServerProperties().getServlet().getSession().getTimeout());
@@ -90,4 +100,14 @@ class SessionAutoConfigurationMongoTests extends AbstractSessionAutoConfiguratio
 		};
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class CustomizerConfiguration {
+
+		@Bean
+		SessionRepositoryCustomizer<MongoIndexedSessionRepository> sessionRepositoryCustomizer() {
+			return (repository) -> repository.setCollectionName("customized");
+		}
+
+	}
+
 }
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationRedisTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationRedisTests.java
index 781b388fff..e98b88fc0a 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationRedisTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationRedisTests.java
@@ -32,10 +32,13 @@ import org.springframework.boot.test.context.assertj.AssertableWebApplicationCon
 import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
 import org.springframework.boot.testsupport.testcontainers.RedisContainer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
 import org.springframework.data.redis.connection.RedisConnection;
 import org.springframework.data.redis.connection.RedisConnectionFactory;
 import org.springframework.session.FlushMode;
 import org.springframework.session.SaveMode;
+import org.springframework.session.config.SessionRepositoryCustomizer;
 import org.springframework.session.data.mongo.MongoIndexedSessionRepository;
 import org.springframework.session.data.redis.RedisIndexedSessionRepository;
 import org.springframework.session.data.redis.RedisSessionRepository;
@@ -165,6 +168,32 @@ class SessionAutoConfigurationRedisTests extends AbstractSessionAutoConfiguratio
 
 	}
 
+	@Test
+	void whenTheUserDefinesTheirOwnSessionRepositoryCustomizerThenDefaultConfigurationIsOverwritten() {
+		this.contextRunner.withConfiguration(AutoConfigurations.of(RedisAutoConfiguration.class))
+			.withUserConfiguration(CustomizerConfiguration.class)
+			.withPropertyValues("spring.session.redis.flush-mode=immediate",
+					"spring.data.redis.host=" + redis.getHost(), "spring.data.redis.port=" + redis.getFirstMappedPort())
+			.run((context) -> {
+				RedisSessionRepository repository = validateSessionRepository(context, RedisSessionRepository.class);
+				assertThat(repository).hasFieldOrPropertyWithValue("flushMode", FlushMode.ON_SAVE);
+			});
+	}
+
+	@Test
+	void whenIndexedAndTheUserDefinesTheirOwnSessionRepositoryCustomizerThenDefaultConfigurationIsOverwritten() {
+		this.contextRunner.withConfiguration(AutoConfigurations.of(RedisAutoConfiguration.class))
+			.withUserConfiguration(IndexedCustomizerConfiguration.class)
+			.withPropertyValues("spring.session.redis.repository-type=indexed",
+					"spring.session.redis.flush-mode=immediate", "spring.data.redis.host=" + redis.getHost(),
+					"spring.data.redis.port=" + redis.getFirstMappedPort())
+			.run((context) -> {
+				RedisIndexedSessionRepository repository = validateSessionRepository(context,
+						RedisIndexedSessionRepository.class);
+				assertThat(repository).hasFieldOrPropertyWithValue("flushMode", FlushMode.ON_SAVE);
+			});
+	}
+
 	private ContextConsumer<AssertableWebApplicationContext> validateSpringSessionUsesDefaultRedis(String keyNamespace,
 			FlushMode flushMode, SaveMode saveMode) {
 		return (context) -> {
@@ -213,4 +242,24 @@ class SessionAutoConfigurationRedisTests extends AbstractSessionAutoConfiguratio
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class CustomizerConfiguration {
+
+		@Bean
+		SessionRepositoryCustomizer<RedisSessionRepository> sessionRepositoryCustomizer() {
+			return (repository) -> repository.setFlushMode(FlushMode.ON_SAVE);
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class IndexedCustomizerConfiguration {
+
+		@Bean
+		SessionRepositoryCustomizer<RedisIndexedSessionRepository> sessionRepositoryCustomizer() {
+			return (repository) -> repository.setFlushMode(FlushMode.ON_SAVE);
+		}
+
+	}
+
 }