diff --git a/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesAutoConfigurationTests.java b/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesAutoConfigurationTests.java
index 84347fc0092..9d3fb42c0a2 100644
--- a/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesAutoConfigurationTests.java
+++ b/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesAutoConfigurationTests.java
@@ -27,11 +27,12 @@ import org.mockito.Mockito;
 import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.boot.TestUtils;
 import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
-import org.springframework.boot.autoconfigure.web.ServerPropertiesAutoConfiguration;
 import org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext;
 import org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainerFactory;
+import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer;
 import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizerBeanPostProcessor;
 import org.springframework.boot.context.embedded.EmbeddedServletContainerFactory;
+import org.springframework.boot.context.embedded.jetty.JettyEmbeddedServletContainerFactory;
 import org.springframework.boot.context.embedded.properties.ServerProperties;
 import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
 import org.springframework.context.annotation.Bean;
@@ -76,7 +77,7 @@ public class ServerPropertiesAutoConfigurationTests {
 		this.context.refresh();
 		ServerProperties server = this.context.getBean(ServerProperties.class);
 		assertNotNull(server);
-		assertEquals(9000, server.getPort());
+		assertEquals(9000, server.getPort().intValue());
 		Mockito.verify(containerFactory).setPort(9000);
 	}
 
@@ -86,12 +87,44 @@ public class ServerPropertiesAutoConfigurationTests {
 		this.context = new AnnotationConfigEmbeddedWebApplicationContext();
 		this.context.register(Config.class, ServerPropertiesAutoConfiguration.class,
 				PropertyPlaceholderAutoConfiguration.class);
-		TestUtils.addEnviroment(this.context, "server.tomcat.basedir:target/foo");
+		TestUtils.addEnviroment(this.context, "server.tomcat.basedir:target/foo",
+				"server.port:9000");
 		this.context.refresh();
 		ServerProperties server = this.context.getBean(ServerProperties.class);
 		assertNotNull(server);
 		assertEquals(new File("target/foo"), server.getTomcat().getBasedir());
-		Mockito.verify(containerFactory).setPort(8080);
+		Mockito.verify(containerFactory).setPort(9000);
+	}
+
+	@Test
+	public void customizeWithContainerFactory() throws Exception {
+		this.context = new AnnotationConfigEmbeddedWebApplicationContext();
+		this.context.register(CustomContainerConfig.class,
+				ServerPropertiesAutoConfiguration.class,
+				PropertyPlaceholderAutoConfiguration.class);
+		this.context.refresh();
+		containerFactory = this.context
+				.getBean(ConfigurableEmbeddedServletContainerFactory.class);
+		ServerProperties server = this.context.getBean(ServerProperties.class);
+		assertNotNull(server);
+		// The server.port environment property was not explicitly set so the container
+		// factory should take precedence...
+		assertEquals(3000, containerFactory.getPort());
+	}
+
+	@Test
+	public void customizeTomcatWithCustomizer() throws Exception {
+		containerFactory = Mockito.mock(TomcatEmbeddedServletContainerFactory.class);
+		this.context = new AnnotationConfigEmbeddedWebApplicationContext();
+		this.context.register(Config.class, CustomizeConfig.class,
+				ServerPropertiesAutoConfiguration.class,
+				PropertyPlaceholderAutoConfiguration.class);
+		this.context.refresh();
+		ServerProperties server = this.context.getBean(ServerProperties.class);
+		assertNotNull(server);
+		// The server.port environment property was not explicitly set so the container
+		// customizer should take precedence...
+		Mockito.verify(containerFactory).setPort(3000);
 	}
 
 	@Test
@@ -120,6 +153,39 @@ public class ServerPropertiesAutoConfigurationTests {
 
 	}
 
+	@Configuration
+	protected static class CustomContainerConfig {
+
+		@Bean
+		public EmbeddedServletContainerFactory containerFactory() {
+			JettyEmbeddedServletContainerFactory factory = new JettyEmbeddedServletContainerFactory();
+			factory.setPort(3000);
+			return factory;
+		}
+
+		@Bean
+		public EmbeddedServletContainerCustomizerBeanPostProcessor embeddedServletContainerCustomizerBeanPostProcessor() {
+			return new EmbeddedServletContainerCustomizerBeanPostProcessor();
+		}
+
+	}
+
+	@Configuration
+	protected static class CustomizeConfig {
+
+		@Bean
+		public EmbeddedServletContainerCustomizer containerCustomizer() {
+			return new EmbeddedServletContainerCustomizer() {
+
+				@Override
+				public void customize(ConfigurableEmbeddedServletContainerFactory factory) {
+					factory.setPort(3000);
+				}
+			};
+		}
+
+	}
+
 	@Configuration
 	protected static class MutiServerPropertiesBeanConfig {
 
diff --git a/spring-boot/src/main/java/org/springframework/boot/context/embedded/properties/ServerProperties.java b/spring-boot/src/main/java/org/springframework/boot/context/embedded/properties/ServerProperties.java
index b6d3996b7a7..a91e8b7c23a 100644
--- a/spring-boot/src/main/java/org/springframework/boot/context/embedded/properties/ServerProperties.java
+++ b/spring-boot/src/main/java/org/springframework/boot/context/embedded/properties/ServerProperties.java
@@ -47,11 +47,11 @@ import org.springframework.util.StringUtils;
 @ConfigurationProperties(name = "server", ignoreUnknownFields = false)
 public class ServerProperties implements EmbeddedServletContainerCustomizer {
 
-	private int port = 8080;
+	private Integer port;
 
 	private InetAddress address;
 
-	private int sessionTimeout = 30;
+	private Integer sessionTimeout;
 
 	@NotNull
 	private String contextPath = "";
@@ -70,11 +70,11 @@ public class ServerProperties implements EmbeddedServletContainerCustomizer {
 		this.contextPath = contextPath;
 	}
 
-	public int getPort() {
+	public Integer getPort() {
 		return this.port;
 	}
 
-	public void setPort(int port) {
+	public void setPort(Integer port) {
 		this.port = port;
 	}
 
@@ -86,11 +86,11 @@ public class ServerProperties implements EmbeddedServletContainerCustomizer {
 		this.address = address;
 	}
 
-	public int getSessionTimeout() {
+	public Integer getSessionTimeout() {
 		return this.sessionTimeout;
 	}
 
-	public void setSessionTimeout(int sessionTimeout) {
+	public void setSessionTimeout(Integer sessionTimeout) {
 		this.sessionTimeout = sessionTimeout;
 	}
 
@@ -100,10 +100,18 @@ public class ServerProperties implements EmbeddedServletContainerCustomizer {
 
 	@Override
 	public void customize(ConfigurableEmbeddedServletContainerFactory factory) {
-		factory.setPort(getPort());
-		factory.setAddress(getAddress());
-		factory.setContextPath(getContextPath());
-		factory.setSessionTimeout(getSessionTimeout());
+		if (getPort() != null) {
+			factory.setPort(getPort());
+		}
+		if (getAddress() != null) {
+			factory.setAddress(getAddress());
+		}
+		if (getContextPath() != null) {
+			factory.setContextPath(getContextPath());
+		}
+		if (getSessionTimeout() != null) {
+			factory.setSessionTimeout(getSessionTimeout());
+		}
 		if (factory instanceof TomcatEmbeddedServletContainerFactory) {
 			getTomcat().customizeTomcat((TomcatEmbeddedServletContainerFactory) factory);
 		}
diff --git a/spring-boot/src/test/java/org/springframework/boot/context/embedded/properties/ServerPropertiesTests.java b/spring-boot/src/test/java/org/springframework/boot/context/embedded/properties/ServerPropertiesTests.java
index 6a796e67ef5..bda19a6b82f 100644
--- a/spring-boot/src/test/java/org/springframework/boot/context/embedded/properties/ServerPropertiesTests.java
+++ b/spring-boot/src/test/java/org/springframework/boot/context/embedded/properties/ServerPropertiesTests.java
@@ -24,7 +24,6 @@ import java.util.Map;
 import org.junit.Test;
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.boot.bind.RelaxedDataBinder;
-import org.springframework.boot.context.embedded.properties.ServerProperties;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -51,7 +50,7 @@ public class ServerPropertiesTests {
 	public void testPortBinding() throws Exception {
 		new RelaxedDataBinder(this.properties, "server").bind(new MutablePropertyValues(
 				Collections.singletonMap("server.port", "9000")));
-		assertEquals(9000, this.properties.getPort());
+		assertEquals(9000, this.properties.getPort().intValue());
 	}
 
 	@Test