diff --git a/src/main/java/org/springframework/data/mapping/model/BasicPersistentEntity.java b/src/main/java/org/springframework/data/mapping/model/BasicPersistentEntity.java
index a3945ab32..546e79c09 100644
--- a/src/main/java/org/springframework/data/mapping/model/BasicPersistentEntity.java
+++ b/src/main/java/org/springframework/data/mapping/model/BasicPersistentEntity.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2016 by the original author(s).
+ * Copyright 2011-2017 by the original author(s).
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -403,9 +403,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	public PersistentPropertyAccessor getPropertyAccessor(Object bean) {
 
 		Assert.notNull(bean, "Target bean must not be null!");
-
-		Assert.isTrue(getType().isInstance(bean),
-				String.format(TYPE_MISMATCH, bean.getClass().getName(), getType().getName()));
+		assertBeanType(bean);
 
 		return new BeanWrapper<Object>(bean);
 	}
@@ -418,11 +416,18 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	public IdentifierAccessor getIdentifierAccessor(Object bean) {
 
 		Assert.notNull(bean, "Target bean must not be null!");
-		Assert.isTrue(getType().isInstance(bean), "Target bean is not of type of the persistent entity!");
+		assertBeanType(bean);
 
 		return hasIdProperty() ? new IdPropertyIdentifierAccessor(this, bean) : NullReturningIdentifierAccessor.INSTANCE;
 	}
 
+	private void assertBeanType(Object bean) {
+
+		if (!getType().isInstance(bean)) {
+			throw new IllegalArgumentException(String.format(TYPE_MISMATCH, bean.getClass().getName(), getType().getName()));
+		}
+	}
+
 	/**
 	 * A null-object implementation of {@link IdentifierAccessor} to be able to return an accessor for entities that do
 	 * not have an identifier property.