diff --git a/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/bootstrap/ConfigServerBootstrapApplicationListener.java b/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/bootstrap/ConfigServerBootstrapApplicationListener.java
index 06e9ad5b..e0d0c4ef 100644
--- a/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/bootstrap/ConfigServerBootstrapApplicationListener.java
+++ b/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/bootstrap/ConfigServerBootstrapApplicationListener.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2019 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -18,8 +18,10 @@ package org.springframework.cloud.config.server.bootstrap;
 
 import java.util.Collections;
 
+import org.springframework.boot.SpringApplication;
 import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.boot.context.event.ApplicationEnvironmentPreparedEvent;
+import org.springframework.boot.env.EnvironmentPostProcessor;
 import org.springframework.context.ApplicationListener;
 import org.springframework.core.Ordered;
 import org.springframework.core.env.ConfigurableEnvironment;
@@ -43,10 +45,15 @@ import org.springframework.core.env.PropertySource;
  * This listener is only to prevent it from using HTTP to contact itself.
  *
  * @author Dave Syer
+ * @author Ryan Baxter
  *
  */
+// TODO We changed this class from an ApplicationListener to an EnvironmentPostProcessor
+// but did not change the class name to avoid breaking anyone in a minor release.
+// In the next major it will be safe to change the class name and remove the
+// ApplicationListener interface.
 public class ConfigServerBootstrapApplicationListener
-		implements ApplicationListener<ApplicationEnvironmentPreparedEvent>, Ordered {
+		implements ApplicationListener<ApplicationEnvironmentPreparedEvent>, EnvironmentPostProcessor, Ordered {
 
 	/**
 	 * Default order of the bootstrap application listener.
@@ -58,6 +65,15 @@ public class ConfigServerBootstrapApplicationListener
 	private PropertySource<?> propertySource = new MapPropertySource("configServerClient",
 			Collections.<String, Object>singletonMap("spring.cloud.config.enabled", "false"));
 
+	@Override
+	public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
+		if (!environment.resolvePlaceholders("${spring.cloud.config.enabled:false}").equalsIgnoreCase("true")) {
+			if (!environment.getPropertySources().contains(this.propertySource.getName())) {
+				environment.getPropertySources().addLast(this.propertySource);
+			}
+		}
+	}
+
 	@Override
 	public int getOrder() {
 		return this.order;
@@ -69,12 +85,7 @@ public class ConfigServerBootstrapApplicationListener
 
 	@Override
 	public void onApplicationEvent(ApplicationEnvironmentPreparedEvent event) {
-		ConfigurableEnvironment environment = event.getEnvironment();
-		if (!environment.resolvePlaceholders("${spring.cloud.config.enabled:false}").equalsIgnoreCase("true")) {
-			if (!environment.getPropertySources().contains(this.propertySource.getName())) {
-				environment.getPropertySources().addLast(this.propertySource);
-			}
-		}
+		postProcessEnvironment(event.getEnvironment(), event.getSpringApplication());
 	}
 
 }
diff --git a/spring-cloud-config-server/src/main/resources/META-INF/spring.factories b/spring-cloud-config-server/src/main/resources/META-INF/spring.factories
index 906a6cf4..31eb4d95 100644
--- a/spring-cloud-config-server/src/main/resources/META-INF/spring.factories
+++ b/spring-cloud-config-server/src/main/resources/META-INF/spring.factories
@@ -2,9 +2,11 @@
 org.springframework.cloud.bootstrap.BootstrapConfiguration=\
 org.springframework.cloud.config.server.bootstrap.ConfigServerBootstrapConfiguration,\
 org.springframework.cloud.config.server.config.EncryptionAutoConfiguration
-# Application listeners
-org.springframework.context.ApplicationListener=\
+
+# Environment PostProcessor
+org.springframework.boot.env.EnvironmentPostProcessor=\
 org.springframework.cloud.config.server.bootstrap.ConfigServerBootstrapApplicationListener
+
 # Autoconfiguration
 org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
 org.springframework.cloud.config.server.config.ConfigServerAutoConfiguration,\