diff --git a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/AuthenticationManagerConfiguration.java b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/AuthenticationManagerConfiguration.java
index 45c2b846e8..059ffa9e0e 100644
--- a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/AuthenticationManagerConfiguration.java
+++ b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/AuthenticationManagerConfiguration.java
@@ -16,6 +16,7 @@
 
 package org.springframework.boot.autoconfigure.security;
 
+import java.lang.reflect.Field;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
@@ -46,6 +47,7 @@ import org.springframework.security.config.annotation.authentication.configurati
 import org.springframework.security.config.annotation.authentication.configurers.GlobalAuthenticationConfigurerAdapter;
 import org.springframework.security.config.annotation.authentication.configurers.provisioning.InMemoryUserDetailsManagerConfigurer;
 import org.springframework.stereotype.Component;
+import org.springframework.util.ReflectionUtils;
 
 /**
  * Configuration for a Spring Security in-memory {@link AuthenticationManager}. Can be
@@ -171,9 +173,21 @@ public class AuthenticationManagerConfiguration {
 			Set<String> roles = new LinkedHashSet<String>(user.getRole());
 			withUser(user.getName()).password(user.getPassword()).roles(
 					roles.toArray(new String[roles.size()]));
+			setField(auth, "defaultUserDetailsService", getUserDetailsService());
 			super.configure(auth);
 		}
 
+		private void setField(Object target, String name, Object value) {
+			try {
+				Field field = ReflectionUtils.findField(target.getClass(), name);
+				ReflectionUtils.makeAccessible(field);
+				ReflectionUtils.setField(field, target, value);
+			}
+			catch (Exception e) {
+				logger.info("Could not set " + name);
+			}
+		}
+
 	}
 
 	/**
diff --git a/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/security/SecurityAutoConfigurationTests.java b/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/security/SecurityAutoConfigurationTests.java
index f743f6da58..77375b2d96 100644
--- a/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/security/SecurityAutoConfigurationTests.java
+++ b/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/security/SecurityAutoConfigurationTests.java
@@ -49,6 +49,7 @@ import org.springframework.security.config.annotation.web.configuration.WebSecur
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.AuthenticationException;
 import org.springframework.security.core.authority.AuthorityUtils;
+import org.springframework.security.core.userdetails.UserDetailsService;
 import org.springframework.security.web.FilterChainProxy;
 import org.springframework.security.web.SecurityFilterChain;
 import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
@@ -190,6 +191,19 @@ public class SecurityAutoConfigurationTests {
 				this.context.getBean(AuthenticationManager.class));
 	}
 
+	@Test
+	public void testDefaultAuthenticationManagerMakesUserDetailsAvailable()
+			throws Exception {
+		this.context = new AnnotationConfigWebApplicationContext();
+		this.context.setServletContext(new MockServletContext());
+		this.context.register(UserDetailsSecurityCustomizer.class,
+				SecurityAutoConfiguration.class, ServerPropertiesAutoConfiguration.class,
+				PropertyPlaceholderAutoConfiguration.class);
+		this.context.refresh();
+		assertNotNull(this.context.getBean(UserDetailsSecurityCustomizer.class)
+				.getUserDetails().loadUserByUsername("user"));
+	}
+
 	@Test
 	public void testOverrideAuthenticationManagerAndInjectIntoSecurityFilter()
 			throws Exception {
@@ -380,4 +394,21 @@ public class SecurityAutoConfigurationTests {
 
 	}
 
+	@Configuration
+	protected static class UserDetailsSecurityCustomizer extends
+			WebSecurityConfigurerAdapter {
+
+		private UserDetailsService userDetails;
+
+		@Override
+		protected void configure(HttpSecurity http) throws Exception {
+			this.userDetails = http.getSharedObject(UserDetailsService.class);
+		}
+
+		public UserDetailsService getUserDetails() {
+			return this.userDetails;
+		}
+
+	}
+
 }