diff --git a/smoke-test/spring-boot-smoke-test-data-jdbc/src/main/java/smoketest/data/jdbc/Customer.java b/smoke-test/spring-boot-smoke-test-data-jdbc/src/main/java/smoketest/data/jdbc/Customer.java
index cb7a8686c30..0e5c5416191 100644
--- a/smoke-test/spring-boot-smoke-test-data-jdbc/src/main/java/smoketest/data/jdbc/Customer.java
+++ b/smoke-test/spring-boot-smoke-test-data-jdbc/src/main/java/smoketest/data/jdbc/Customer.java
@@ -18,38 +18,40 @@ package smoketest.data.jdbc;
 
 import java.time.LocalDate;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.data.annotation.Id;
 
 public class Customer {
 
 	@Id
-	private Long id;
+	private @Nullable Long id;
 
-	private String firstName;
+	private @Nullable String firstName;
 
-	private LocalDate dateOfBirth;
+	private @Nullable LocalDate dateOfBirth;
 
-	public Long getId() {
+	public @Nullable Long getId() {
 		return this.id;
 	}
 
-	public void setId(Long id) {
+	public void setId(@Nullable Long id) {
 		this.id = id;
 	}
 
-	public String getFirstName() {
+	public @Nullable String getFirstName() {
 		return this.firstName;
 	}
 
-	public void setFirstName(String firstName) {
+	public void setFirstName(@Nullable String firstName) {
 		this.firstName = firstName;
 	}
 
-	public LocalDate getDateOfBirth() {
+	public @Nullable LocalDate getDateOfBirth() {
 		return this.dateOfBirth;
 	}
 
-	public void setDateOfBirth(LocalDate dateOfBirth) {
+	public void setDateOfBirth(@Nullable LocalDate dateOfBirth) {
 		this.dateOfBirth = dateOfBirth;
 	}
 
diff --git a/smoke-test/spring-boot-smoke-test-data-jdbc/src/main/java/smoketest/data/jdbc/package-info.java b/smoke-test/spring-boot-smoke-test-data-jdbc/src/main/java/smoketest/data/jdbc/package-info.java
new file mode 100644
index 00000000000..2e0b017eb2c
--- /dev/null
+++ b/smoke-test/spring-boot-smoke-test-data-jdbc/src/main/java/smoketest/data/jdbc/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-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.
+ */
+
+@NullMarked
+package smoketest.data.jdbc;
+
+import org.jspecify.annotations.NullMarked;