diff --git a/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/web/trace/servlet/TraceableHttpServletRequest.java b/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/web/trace/servlet/TraceableHttpServletRequest.java
index eb74733ff5a..b6ea52577ec 100644
--- a/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/web/trace/servlet/TraceableHttpServletRequest.java
+++ b/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/web/trace/servlet/TraceableHttpServletRequest.java
@@ -19,7 +19,7 @@ package org.springframework.boot.actuate.web.trace.servlet;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Enumeration;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -85,17 +85,9 @@ final class TraceableHttpServletRequest implements TraceableRequest {
 		Enumeration<String> names = this.request.getHeaderNames();
 		while (names.hasMoreElements()) {
 			String name = names.nextElement();
-			headers.put(name, toList(this.request.getHeaders(name)));
+			headers.put(name, Collections.list(this.request.getHeaders(name)));
 		}
 		return headers;
 	}
 
-	private List<String> toList(Enumeration<String> enumeration) {
-		List<String> list = new ArrayList<>();
-		while (enumeration.hasMoreElements()) {
-			list.add(enumeration.nextElement());
-		}
-		return list;
-	}
-
 }
diff --git a/spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/restart/classloader/RestartClassLoaderTests.java b/spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/restart/classloader/RestartClassLoaderTests.java
index be50d95ffec..8327df6993e 100644
--- a/spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/restart/classloader/RestartClassLoaderTests.java
+++ b/spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/restart/classloader/RestartClassLoaderTests.java
@@ -23,7 +23,7 @@ import java.io.InputStream;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Enumeration;
 import java.util.List;
 import java.util.jar.JarOutputStream;
@@ -212,13 +212,8 @@ public class RestartClassLoaderTests {
 	}
 
 	private <T> List<T> toList(Enumeration<T> enumeration) {
-		List<T> list = new ArrayList<>();
-		if (enumeration != null) {
-			while (enumeration.hasMoreElements()) {
-				list.add(enumeration.nextElement());
-			}
-		}
-		return list;
+		return (enumeration != null) ? Collections.list(enumeration)
+				: Collections.<T>emptyList();
 	}
 
 }