diff --git a/spring-core/src/main/java/org/springframework/util/ClassUtils.java b/spring-core/src/main/java/org/springframework/util/ClassUtils.java
index 4a7b9e8f93..b10f7f8d53 100644
--- a/spring-core/src/main/java/org/springframework/util/ClassUtils.java
+++ b/spring-core/src/main/java/org/springframework/util/ClassUtils.java
@@ -121,10 +121,11 @@ public abstract class ClassUtils {
 		primitiveWrapperTypeMap.put(Long.class, long.class);
 		primitiveWrapperTypeMap.put(Short.class, short.class);
 
-		primitiveWrapperTypeMap.forEach((key, value) -> {
-			primitiveTypeToWrapperMap.put(value, key);
-			registerCommonClasses(key);
-		});
+		// Map entry iteration is less expensive to initialize than forEach with lambdas
+		for (Map.Entry<Class<?>, Class<?>> entry : primitiveWrapperTypeMap.entrySet()) {
+			primitiveTypeToWrapperMap.put(entry.getValue(), entry.getKey());
+			registerCommonClasses(entry.getKey());
+		}
 
 		Set<Class<?>> primitiveTypes = new HashSet<>(32);
 		primitiveTypes.addAll(primitiveWrapperTypeMap.values());