diff --git a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration.java b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration.java
index b7ae373235..bb7cc67e01 100644
--- a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration.java
+++ b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration.java
@@ -20,6 +20,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.Date;
 import java.util.List;
+import java.util.Map;
 
 import javax.servlet.Servlet;
 
@@ -54,6 +55,7 @@ import org.springframework.core.io.Resource;
 import org.springframework.format.Formatter;
 import org.springframework.format.FormatterRegistry;
 import org.springframework.format.datetime.DateFormatter;
+import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.validation.DefaultMessageCodesResolver;
 import org.springframework.validation.MessageCodesResolver;
@@ -68,6 +70,7 @@ import org.springframework.web.servlet.LocaleResolver;
 import org.springframework.web.servlet.View;
 import org.springframework.web.servlet.ViewResolver;
 import org.springframework.web.servlet.config.annotation.AsyncSupportConfigurer;
+import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
 import org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration;
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.ResourceChainRegistration;
@@ -155,6 +158,14 @@ public class WebMvcAutoConfiguration {
 			}
 		}
 
+		@Override
+		public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
+			Map<String, MediaType> mediaTypes = this.mvcProperties.getMediaTypes();
+			for (String extension : mediaTypes.keySet()) {
+				configurer.mediaType(extension, mediaTypes.get(extension));
+			}
+		}
+
 		@Bean
 		@ConditionalOnMissingBean
 		public InternalResourceViewResolver defaultViewResolver() {
diff --git a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcProperties.java b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcProperties.java
index 92022d076e..b887aba20b 100644
--- a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcProperties.java
+++ b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/WebMvcProperties.java
@@ -16,10 +16,13 @@
 
 package org.springframework.boot.autoconfigure.web;
 
+import java.util.LinkedHashMap;
 import java.util.Locale;
+import java.util.Map;
 
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.http.MediaType;
 import org.springframework.validation.DefaultMessageCodesResolver;
 
 /**
@@ -63,6 +66,11 @@ public class WebMvcProperties {
 
 	private final View view = new View();
 
+	/**
+	 * Maps file extensions to media types for content negotiation, e.g. yml->text/yaml.
+	 */
+	private Map<String, MediaType> mediaTypes = new LinkedHashMap<String, MediaType>();
+
 	public DefaultMessageCodesResolver.Format getMessageCodesResolverFormat() {
 		return this.messageCodesResolverFormat;
 	}
@@ -113,6 +121,14 @@ public class WebMvcProperties {
 		return this.view;
 	}
 
+	public Map<String, MediaType> getMediaTypes() {
+		return this.mediaTypes;
+	}
+
+	public void setMediaTypes(Map<String, MediaType> mediaTypes) {
+		this.mediaTypes = mediaTypes;
+	}
+
 	public static class Async {
 
 		/**
diff --git a/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfigurationTests.java b/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfigurationTests.java
index 59e8178079..f8bbbbee19 100644
--- a/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfigurationTests.java
+++ b/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/WebMvcAutoConfigurationTests.java
@@ -53,6 +53,7 @@ import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
+import org.springframework.web.accept.ContentNegotiationManager;
 import org.springframework.web.bind.support.ConfigurableWebBindingInitializer;
 import org.springframework.web.filter.HttpPutFormContentFilter;
 import org.springframework.web.servlet.HandlerAdapter;
@@ -90,6 +91,7 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 
 /**
  * Tests for {@link WebMvcAutoConfiguration}.
@@ -430,6 +432,16 @@ public class WebMvcAutoConfigurationTests {
 		assertEquals(123456L, actual);
 	}
 
+	@Test
+	public void customMediaTypes() throws Exception {
+		load("spring.mvc.mediaTypes.yaml:text/yaml");
+		RequestMappingHandlerAdapter adapter = this.context
+				.getBean(RequestMappingHandlerAdapter.class);
+		ContentNegotiationManager actual = (ContentNegotiationManager) ReflectionTestUtils
+				.getField(adapter, "contentNegotiationManager");
+		assertTrue(actual.getAllFileExtensions().contains("yaml"));
+	}
+
 	@Test
 	public void httpPutFormContentFilterIsAutoConfigured() {
 		load();