diff --git a/spring-session-jdbc/src/integration-test/java/org/springframework/session/jdbc/HsqldbJdbcIndexedSessionRepositoryCustomizerITests.java b/spring-session-jdbc/src/integration-test/java/org/springframework/session/jdbc/HsqldbJdbcIndexedSessionRepositoryCustomizerITests.java
new file mode 100644
index 000000000..526f3f964
--- /dev/null
+++ b/spring-session-jdbc/src/integration-test/java/org/springframework/session/jdbc/HsqldbJdbcIndexedSessionRepositoryCustomizerITests.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2014-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.session.jdbc;
+
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.test.context.web.WebAppConfiguration;
+
+/**
+ * Integration tests for {@link JdbcIndexedSessionRepository} using HsqlDB with
+ * {@link HsqldbJdbcIndexedSessionRepositoryCustomizer}.
+ *
+ * @author Martin Ashby
+ */
+@ExtendWith(SpringExtension.class)
+@WebAppConfiguration
+@ContextConfiguration
+class HsqldbJdbcIndexedSessionRepositoryCustomizerITests extends HsqldbJdbcIndexedSessionRepositoryITests {
+
+	@Configuration
+	static class CustomizerConfig extends Config {
+
+		@Bean
+		HsqldbJdbcIndexedSessionRepositoryCustomizer postgreSqlJdbcIndexedSessionRepositoryCustomizer() {
+			return new PostgreSqlJdbcIndexedSessionRepositoryCustomizer();
+		}
+
+	}
+
+}
diff --git a/spring-session-jdbc/src/main/java/org/springframework/session/jdbc/HsqldbJdbcIndexedSessionRepositoryCustomizer.java b/spring-session-jdbc/src/main/java/org/springframework/session/jdbc/HsqldbJdbcIndexedSessionRepositoryCustomizer.java
new file mode 100644
index 000000000..6042410f1
--- /dev/null
+++ b/spring-session-jdbc/src/main/java/org/springframework/session/jdbc/HsqldbJdbcIndexedSessionRepositoryCustomizer.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2014-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.session.jdbc;
+
+import org.springframework.session.config.SessionRepositoryCustomizer;
+
+/**
+ * A {@link SessionRepositoryCustomizer} implementation that applies HsqlDB specific
+ * optimized SQL statements to {@link JdbcIndexedSessionRepository}.
+ *
+ * @author Martin Ashby
+ * @since 3.5.5
+ */
+public class HsqldbJdbcIndexedSessionRepositoryCustomizer
+		implements SessionRepositoryCustomizer<JdbcIndexedSessionRepository> {
+
+	private static final String CREATE_SESSION_ATTRIBUTE_QUERY = """
+			MERGE INTO %TABLE_NAME%_ATTRIBUTES AS T
+			    USING (VALUES (?, ?, CAST (? AS LONGVARBINARY))) AS I (SESSION_PRIMARY_ID, ATTRIBUTE_NAME, ATTRIBUTE_BYTES)
+			    ON (T.SESSION_PRIMARY_ID = I.SESSION_PRIMARY_ID AND T.ATTRIBUTE_NAME = I.ATTRIBUTE_NAME)
+			    WHEN MATCHED THEN UPDATE SET T.ATTRIBUTE_BYTES = I.ATTRIBUTE_BYTES
+			    WHEN NOT MATCHED THEN INSERT VALUES I.SESSION_PRIMARY_ID, I.ATTRIBUTE_NAME, I.ATTRIBUTE_BYTES
+			""";
+
+	@Override
+	public void customize(JdbcIndexedSessionRepository sessionRepository) {
+		sessionRepository.setCreateSessionAttributeQuery(CREATE_SESSION_ATTRIBUTE_QUERY);
+	}
+
+}