diff --git a/spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java b/spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java
index c4f53525306..afabaac09df 100644
--- a/spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java
+++ b/spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java
@@ -92,6 +92,7 @@ import org.springframework.util.StringUtils;
  * @author Juergen Hoeller
  * @author Sam Brannen
  * @author Costin Leau
+ * @author Chris Beams
  * @since 16 April 2001
  * @see StaticListableBeanFactory
  * @see PropertiesBeanDefinitionReader
@@ -135,6 +136,12 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 	/** Map of bean definition objects, keyed by bean name */
 	private final Map<String, BeanDefinition> beanDefinitionMap = new ConcurrentHashMap<String, BeanDefinition>();
 
+	/** Map of singleton bean names keyed by bean class */
+	private final Map<Class<?>, String[]> singletonBeanNamesByType = new ConcurrentHashMap<Class<?>, String[]>();
+
+	/** Map of non-singleton bean names keyed by bean class */
+	private final Map<Class<?>, String[]> nonSingletonBeanNamesByType = new ConcurrentHashMap<Class<?>, String[]>();
+
 	/** List of bean definition names, in registration order */
 	private final List<String> beanDefinitionNames = new ArrayList<String>();
 
@@ -301,6 +308,21 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 	}
 
 	public String[] getBeanNamesForType(Class<?> type, boolean includeNonSingletons, boolean allowEagerInit) {
+		if (type == null || !allowEagerInit) {
+			return this.doGetBeanNamesForType(type, includeNonSingletons, allowEagerInit);
+		}
+		Map<Class<?>, String[]> cache = includeNonSingletons ?
+				this.nonSingletonBeanNamesByType : this.singletonBeanNamesByType;
+		String[] resolvedBeanNames = cache.get(type);
+		if (resolvedBeanNames != null) {
+			return resolvedBeanNames;
+		}
+		resolvedBeanNames = this.doGetBeanNamesForType(type, includeNonSingletons, allowEagerInit);
+		cache.put(type, resolvedBeanNames);
+		return resolvedBeanNames;
+	}
+
+	private String[] doGetBeanNamesForType(Class<?> type, boolean includeNonSingletons, boolean allowEagerInit) {
 		List<String> result = new ArrayList<String>();
 
 		// Check all bean definitions.
@@ -671,6 +693,10 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 			destroySingleton(beanName);
 		}
 
+		// Remove any assumptions about by-type mappings
+		this.singletonBeanNamesByType.clear();
+		this.nonSingletonBeanNamesByType.clear();
+
 		// Reset all bean definitions that have the given bean as parent (recursively).
 		for (String bdName : this.beanDefinitionNames) {
 			if (!beanName.equals(bdName)) {
diff --git a/spring-beans/src/test/java/org/springframework/beans/factory/DefaultListableBeanFactoryTests.java b/spring-beans/src/test/java/org/springframework/beans/factory/DefaultListableBeanFactoryTests.java
index 8505da7cba1..c123347482c 100644
--- a/spring-beans/src/test/java/org/springframework/beans/factory/DefaultListableBeanFactoryTests.java
+++ b/spring-beans/src/test/java/org/springframework/beans/factory/DefaultListableBeanFactoryTests.java
@@ -2164,6 +2164,34 @@ public class DefaultListableBeanFactoryTests {
 	}
 
 
+	static class A { }
+	static class B { }
+
+	/**
+	 * Test that by-type bean lookup caching is working effectively by searching for a
+	 * bean of type B 10K times within a container having 1K additional beans of type A.
+	 * Prior to by-type caching, each bean lookup would traverse the entire container
+	 * (all 1001 beans), performing expensive assignability checks, etc. Now these
+	 * operations are necessary only once, providing a dramatic performance improvement.
+	 * On load-free modern hardware (e.g. an 8-core MPB), this method should complete well
+	 * under the 1000 ms timeout, usually ~= 300ms. With caching removed and on the same
+	 * hardware the method will take ~13000 ms. See SPR-6870.
+	 */
+	@Test(timeout=1000)
+	public void testByTypeLookupIsFastEnough() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+
+		for (int i=0; i<1000; i++) {
+			bf.registerBeanDefinition("a"+i, new RootBeanDefinition(A.class));
+		}
+		bf.registerBeanDefinition("b", new RootBeanDefinition(B.class));
+
+		for (int i=0; i<10000; i++) {
+			bf.getBean(B.class);
+		}
+	}
+
+
 	public static class NoDependencies {
 
 		private NoDependencies() {