diff --git a/spring-boot-dependencies/pom.xml b/spring-boot-dependencies/pom.xml
index 37762f8bac5..cd7dfd4762d 100644
--- a/spring-boot-dependencies/pom.xml
+++ b/spring-boot-dependencies/pom.xml
@@ -162,7 +162,7 @@
 		<slf4j.version>1.7.25</slf4j.version>
 		<snakeyaml.version>1.18</snakeyaml.version>
 		<solr.version>6.6.1</solr.version>
-		<spring.version>5.0.0.RC4</spring.version>
+		<spring.version>5.0.0.BUILD-SNAPSHOT</spring.version>
 		<spring-amqp.version>2.0.0.RC1</spring-amqp.version>
 		<spring-cloud-connectors.version>2.0.0.M1</spring-cloud-connectors.version>
 		<spring-batch.version>4.0.0.M3</spring-batch.version>
diff --git a/spring-boot/pom.xml b/spring-boot/pom.xml
index 0a4d4736332..94d046d5551 100644
--- a/spring-boot/pom.xml
+++ b/spring-boot/pom.xml
@@ -351,6 +351,11 @@
 			<artifactId>mariadb-java-client</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.postgresql</groupId>
 			<artifactId>postgresql</artifactId>
diff --git a/spring-boot/src/test/java/org/springframework/boot/StartUpLoggerTests.java b/spring-boot/src/test/java/org/springframework/boot/StartUpLoggerTests.java
index dc467ed1df1..06ca1a0c089 100644
--- a/spring-boot/src/test/java/org/springframework/boot/StartUpLoggerTests.java
+++ b/spring-boot/src/test/java/org/springframework/boot/StartUpLoggerTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -16,33 +16,29 @@
 
 package org.springframework.boot;
 
-import org.apache.commons.logging.impl.SimpleLog;
+import org.apache.commons.logging.Log;
 import org.junit.Test;
 
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.startsWith;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
 
 /**
  * Tests for {@link StartupInfoLogger}.
  *
  * @author Dave Syer
+ * @author Andy Wilkinson
  */
 public class StartUpLoggerTests {
 
-	private final StringBuffer output = new StringBuffer();
-
-	@SuppressWarnings("serial")
-	private final SimpleLog log = new SimpleLog("test") {
-		@Override
-		protected void write(StringBuffer buffer) {
-			StartUpLoggerTests.this.output.append(buffer).append("\n");
-		};
-	};
+	private final Log log = mock(Log.class);
 
 	@Test
 	public void sourceClassIncluded() {
+		given(this.log.isInfoEnabled()).willReturn(true);
 		new StartupInfoLogger(getClass()).logStarting(this.log);
-		assertThat(this.output.toString())
-				.contains("Starting " + getClass().getSimpleName());
+		verify(this.log).info(startsWith("Starting " + getClass().getSimpleName()));
 	}
 
 }