diff --git a/module/spring-boot-data-cassandra/build.gradle b/module/spring-boot-data-cassandra/build.gradle
index 4c57667c70f..42cfd72eb5f 100644
--- a/module/spring-boot-data-cassandra/build.gradle
+++ b/module/spring-boot-data-cassandra/build.gradle
@@ -45,3 +45,11 @@ dependencies {
 
 	testRuntimeOnly("ch.qos.logback:logback-classic")
 }
+
+tasks.named("compileTestJava") {
+	options.nullability.checking = "tests"
+}
+
+tasks.named("compileDockerTestJava") {
+	options.nullability.checking = "tests"
+}
diff --git a/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraAutoConfigurationTests.java b/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraAutoConfigurationTests.java
index 920165d1ffd..d671f9d1524 100644
--- a/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraAutoConfigurationTests.java
+++ b/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraAutoConfigurationTests.java
@@ -19,6 +19,7 @@ package org.springframework.boot.data.cassandra.autoconfigure;
 import java.util.Collections;
 
 import com.datastax.oss.driver.api.core.CqlSession;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
@@ -144,7 +145,7 @@ class DataCassandraAutoConfigurationTests {
 	static class MyConverter implements Converter<Person, String> {
 
 		@Override
-		public String convert(Person o) {
+		public @Nullable String convert(Person o) {
 			return null;
 		}
 
diff --git a/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraReactiveRepositoriesAutoConfigurationTests.java b/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraReactiveRepositoriesAutoConfigurationTests.java
index 522d0dbda00..3329312e436 100644
--- a/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraReactiveRepositoriesAutoConfigurationTests.java
+++ b/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraReactiveRepositoriesAutoConfigurationTests.java
@@ -94,7 +94,9 @@ class DataCassandraReactiveRepositoriesAutoConfigurationTests {
 
 	private ManagedTypes getManagedTypes(ApplicationContext context) {
 		CassandraMappingContext mappingContext = context.getBean(CassandraMappingContext.class);
-		return (ManagedTypes) ReflectionTestUtils.getField(mappingContext, "managedTypes");
+		Object field = ReflectionTestUtils.getField(mappingContext, "managedTypes");
+		assertThat(field).isNotNull();
+		return (ManagedTypes) field;
 	}
 
 	@Configuration(proxyBeanMethods = false)
diff --git a/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraRepositoriesAutoConfigurationTests.java b/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraRepositoriesAutoConfigurationTests.java
index 5a3e084b5a6..4d44d3689b5 100644
--- a/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraRepositoriesAutoConfigurationTests.java
+++ b/module/spring-boot-data-cassandra/src/test/java/org/springframework/boot/data/cassandra/autoconfigure/DataCassandraRepositoriesAutoConfigurationTests.java
@@ -91,7 +91,9 @@ class DataCassandraRepositoriesAutoConfigurationTests {
 
 	private ManagedTypes getManagedTypes(AssertableApplicationContext context) {
 		CassandraMappingContext mappingContext = context.getBean(CassandraMappingContext.class);
-		return (ManagedTypes) ReflectionTestUtils.getField(mappingContext, "managedTypes");
+		Object field = ReflectionTestUtils.getField(mappingContext, "managedTypes");
+		assertThat(field).isNotNull();
+		return (ManagedTypes) field;
 	}
 
 	@Configuration(proxyBeanMethods = false)