diff --git a/spring-aop/src/main/java/org/springframework/aop/scope/ScopedProxyUtils.java b/spring-aop/src/main/java/org/springframework/aop/scope/ScopedProxyUtils.java
index 14b0d06060..b087d9ab70 100644
--- a/spring-aop/src/main/java/org/springframework/aop/scope/ScopedProxyUtils.java
+++ b/spring-aop/src/main/java/org/springframework/aop/scope/ScopedProxyUtils.java
@@ -117,7 +117,7 @@ public abstract class ScopedProxyUtils {
 	 * @see #getTargetBeanName(String)
 	 * @see #isScopedTarget(String)
 	 */
-	public static String getOriginalBeanName(String targetBeanName) {
+	public static String getOriginalBeanName(@Nullable String targetBeanName) {
 		Assert.isTrue(isScopedTarget(targetBeanName), () -> "bean name '" +
 				targetBeanName + "' does not refer to the target of a scoped proxy");
 		return targetBeanName.substring(TARGET_NAME_PREFIX_LENGTH);