diff --git a/spring-aop/src/test/java/org/springframework/aop/scope/ScopedProxyBeanRegistrationCodeFragmentsCustomizerTests.java b/spring-aop/src/test/java/org/springframework/aop/scope/ScopedProxyBeanRegistrationCodeFragmentsCustomizerTests.java
index 4c43a3be3b..b0a4967b02 100644
--- a/spring-aop/src/test/java/org/springframework/aop/scope/ScopedProxyBeanRegistrationCodeFragmentsCustomizerTests.java
+++ b/spring-aop/src/test/java/org/springframework/aop/scope/ScopedProxyBeanRegistrationCodeFragmentsCustomizerTests.java
@@ -133,6 +133,7 @@ class ScopedProxyBeanRegistrationCodeFragmentsCustomizerTests {
 	private void testCompile(BiConsumer<DefaultListableBeanFactory, Compiled> result) {
 		BeanFactoryInitializationAotContribution contribution = this.processor
 				.processAheadOfTime(this.beanFactory);
+		assertThat(contribution).isNotNull();
 		contribution.applyTo(this.generationContext, this.beanFactoryInitializationCode);
 		this.generationContext.writeGeneratedContent();
 		TestCompiler.forSystem().withFiles(this.generatedFiles).printFiles(System.out)
@@ -151,7 +152,7 @@ class ScopedProxyBeanRegistrationCodeFragmentsCustomizerTests {
 	}
 
 
-	class MockBeanFactoryInitializationCode implements BeanFactoryInitializationCode {
+	static class MockBeanFactoryInitializationCode implements BeanFactoryInitializationCode {
 
 		private final GeneratedMethods generatedMethods = new GeneratedMethods();
 
@@ -168,7 +169,7 @@ class ScopedProxyBeanRegistrationCodeFragmentsCustomizerTests {
 		}
 
 		List<MethodReference> getInitializers() {
-			return initializers;
+			return this.initializers;
 		}
 
 	}
diff --git a/spring-core/src/main/java/org/springframework/aot/generate/ClassNameGenerator.java b/spring-core/src/main/java/org/springframework/aot/generate/ClassNameGenerator.java
index 5ff7f02b26..390d628137 100644
--- a/spring-core/src/main/java/org/springframework/aot/generate/ClassNameGenerator.java
+++ b/spring-core/src/main/java/org/springframework/aot/generate/ClassNameGenerator.java
@@ -33,7 +33,6 @@ import org.springframework.util.StringUtils;
  *
  * @author Phillip Webb
  * @since 6.0
- * @see GeneratedClassName
  */
 public final class ClassNameGenerator {
 
diff --git a/spring-core/src/main/java/org/springframework/aot/generate/GeneratedMethod.java b/spring-core/src/main/java/org/springframework/aot/generate/GeneratedMethod.java
index 253c1779b0..678280e72b 100644
--- a/spring-core/src/main/java/org/springframework/aot/generate/GeneratedMethod.java
+++ b/spring-core/src/main/java/org/springframework/aot/generate/GeneratedMethod.java
@@ -20,6 +20,7 @@ import java.util.function.Consumer;
 
 import org.springframework.javapoet.MethodSpec;
 import org.springframework.javapoet.MethodSpec.Builder;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -34,6 +35,7 @@ public final class GeneratedMethod {
 
 	private final String name;
 
+	@Nullable
 	private MethodSpec spec;
 
 
@@ -84,7 +86,7 @@ public final class GeneratedMethod {
 	}
 
 	private void assertNameHasNotBeenChanged(MethodSpec spec) {
-		Assert.isTrue(this.name.toString().equals(spec.name), () -> String
+		Assert.isTrue(this.name.equals(spec.name), () -> String
 				.format("'spec' must use the generated name \"%s\"", this.name));
 	}
 
diff --git a/spring-core/src/main/java/org/springframework/aot/generate/MethodReference.java b/spring-core/src/main/java/org/springframework/aot/generate/MethodReference.java
index 313b679e59..627ba67eec 100644
--- a/spring-core/src/main/java/org/springframework/aot/generate/MethodReference.java
+++ b/spring-core/src/main/java/org/springframework/aot/generate/MethodReference.java
@@ -31,6 +31,7 @@ public final class MethodReference {
 
 	private final Kind kind;
 
+	@Nullable
 	private final ClassName declaringClass;
 
 	private final String methodName;
@@ -109,6 +110,7 @@ public final class MethodReference {
 	 * Return the referenced declaring class.
 	 * @return the declaring class
 	 */
+	@Nullable
 	public ClassName getDeclaringClass() {
 		return this.declaringClass;
 	}
@@ -147,7 +149,7 @@ public final class MethodReference {
 		};
 	}
 
-	private CodeBlock toCodeBlockForInstance(String instanceVariable) {
+	private CodeBlock toCodeBlockForInstance(@Nullable String instanceVariable) {
 		instanceVariable = (instanceVariable != null) ? instanceVariable : "this";
 		return CodeBlock.of("$L::$L", instanceVariable, this.methodName);