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 8b10785d0e9..c9fa24824af 100644
--- a/spring-core/src/main/java/org/springframework/util/ClassUtils.java
+++ b/spring-core/src/main/java/org/springframework/util/ClassUtils.java
@@ -88,13 +88,13 @@ public abstract class ClassUtils {
 	 * Map with primitive wrapper type as key and corresponding primitive
 	 * type as value, for example: Integer.class -> int.class.
 	 */
-	private static final Map<Class<?>, Class<?>> primitiveWrapperTypeMap = new IdentityHashMap<>(8);
+	private static final Map<Class<?>, Class<?>> primitiveWrapperTypeMap = new IdentityHashMap<>(9);
 
 	/**
 	 * Map with primitive type as key and corresponding wrapper
 	 * type as value, for example: int.class -> Integer.class.
 	 */
-	private static final Map<Class<?>, Class<?>> primitiveTypeToWrapperMap = new IdentityHashMap<>(8);
+	private static final Map<Class<?>, Class<?>> primitiveTypeToWrapperMap = new IdentityHashMap<>(9);
 
 	/**
 	 * Map with primitive type name as key and corresponding primitive