diff --git a/src/main/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImpl.java b/src/main/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImpl.java
index b0699ba45..358763ef0 100644
--- a/src/main/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImpl.java
+++ b/src/main/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImpl.java
@@ -88,10 +88,10 @@ class JpaPersistentPropertyImpl extends AnnotationBasedPersistentProperty<JpaPer
 		UPDATEABLE_ANNOTATIONS = Collections.unmodifiableSet(annotations);
 	}
 
-	private final Metamodel metamodel;
 	private final Boolean usePropertyAccess;
 	private final TypeInformation<?> associationTargetType;
 	private final boolean updateable;
+	private final Set<Class<?>> managedTypes;
 
 	/**
 	 * Creates a new {@link JpaPersistentPropertyImpl}
@@ -109,10 +109,10 @@ class JpaPersistentPropertyImpl extends AnnotationBasedPersistentProperty<JpaPer
 
 		Assert.notNull(metamodel, "Metamodel must not be null!");
 
-		this.metamodel = metamodel;
 		this.usePropertyAccess = detectPropertyAccess();
 		this.associationTargetType = isAssociation() ? detectAssociationTargetType() : null;
 		this.updateable = detectUpdatability();
+		this.managedTypes = getManagedTypes(metamodel);
 	}
 
 	/* 
@@ -156,14 +156,7 @@ class JpaPersistentPropertyImpl extends AnnotationBasedPersistentProperty<JpaPer
 	 */
 	@Override
 	public boolean isEntity() {
-
-		for (ManagedType<?> type : metamodel.getManagedTypes()) {
-			if (type.getJavaType().equals(getActualType())) {
-				return true;
-			}
-		}
-
-		return false;
+		return managedTypes.contains(getActualType());
 	}
 
 	/* 
@@ -303,4 +296,27 @@ class JpaPersistentPropertyImpl extends AnnotationBasedPersistentProperty<JpaPer
 
 		return true;
 	}
+
+	/**
+	 * Returns all types managed by the given {@link Metamodel}.
+	 * 
+	 * @param metamodel must not be {@literal null}.
+	 * @return
+	 */
+	private static Set<Class<?>> getManagedTypes(Metamodel metamodel) {
+
+		Set<ManagedType<?>> managedTypes = metamodel.getManagedTypes();
+		Set<Class<?>> types = new HashSet<Class<?>>(managedTypes.size());
+
+		for (ManagedType<?> managedType : metamodel.getManagedTypes()) {
+
+			Class<?> type = managedType.getJavaType();
+
+			if (type != null) {
+				types.add(type);
+			}
+		}
+
+		return Collections.unmodifiableSet(types);
+	}
 }
diff --git a/src/test/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImplUnitTests.java b/src/test/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImplUnitTests.java
index bc2312021..be1c05158 100644
--- a/src/test/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImplUnitTests.java
+++ b/src/test/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImplUnitTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2015 the original author or authors.
+ * Copyright 2013-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@ package org.springframework.data.jpa.mapping;
 
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
 
 import java.util.Collections;
 
@@ -28,6 +29,7 @@ import javax.persistence.Embedded;
 import javax.persistence.ManyToOne;
 import javax.persistence.OneToOne;
 import javax.persistence.Transient;
+import javax.persistence.metamodel.ManagedType;
 import javax.persistence.metamodel.Metamodel;
 
 import org.junit.Before;
@@ -184,6 +186,18 @@ public class JpaPersistentPropertyImplUnitTests {
 		assertThat(getProperty(WithReadOnly.class, "updatable").isWritable(), is(true));
 	}
 
+	/**
+	 * @see DATAJPA-904
+	 */
+	@Test
+	public void isEntityWorksEvenWithManagedTypeWithNullJavaType() {
+
+		ManagedType<?> managedType = mock(ManagedType.class);
+		doReturn(Collections.singleton(managedType)).when(model).getManagedTypes();
+
+		assertThat(getProperty(Sample.class, "other").isEntity(), is(false));
+	}
+
 	private JpaPersistentProperty getProperty(Class<?> ownerType, String propertyName) {
 
 		JpaPersistentEntity<?> entity = context.getPersistentEntity(ownerType);