diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastClientConfiguration.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastClientConfiguration.java
index 2e0267763660..eaf6b1eeaeaa 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastClientConfiguration.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastClientConfiguration.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -29,6 +29,7 @@
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.io.Resource;
+import org.springframework.core.io.ResourceLoader;
 
 /**
  * Configuration for Hazelcast client.
@@ -49,12 +50,15 @@ class HazelcastClientConfiguration {
 	static class HazelcastClientConfigFileConfiguration {
 
 		@Bean
-		HazelcastInstance hazelcastInstance(HazelcastProperties properties) throws IOException {
-			Resource config = properties.resolveConfigLocation();
-			if (config != null) {
-				return new HazelcastClientFactory(config).getHazelcastInstance();
-			}
-			return HazelcastClient.newHazelcastClient();
+		HazelcastInstance hazelcastInstance(HazelcastProperties properties, ResourceLoader resourceLoader)
+				throws IOException {
+			return createHazelcastClientFactory(properties.resolveConfigLocation())
+					.getHazelcastInstance(resourceLoader.getClassLoader());
+		}
+
+		private HazelcastClientFactory createHazelcastClientFactory(Resource config) throws IOException {
+			return (config != null) ? new HazelcastClientFactory(config)
+					: new HazelcastClientFactory(ClientConfig.load());
 		}
 
 	}
@@ -65,6 +69,7 @@ static class HazelcastClientConfigConfiguration {
 
 		@Bean
 		HazelcastInstance hazelcastInstance(ClientConfig config) {
+			// TODO should we replace the ClassLoader here?
 			return new HazelcastClientFactory(config).getHazelcastInstance();
 		}
 
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastClientFactory.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastClientFactory.java
index b1c97535143c..da93afe2b9cd 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastClientFactory.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastClientFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -67,10 +67,22 @@ private ClientConfig getClientConfig(Resource clientConfigLocation) throws IOExc
 	}
 
 	/**
-	 * Get the {@link HazelcastInstance}.
+	 * Get the {@link HazelcastInstance} with the default {@link ClassLoader}.
 	 * @return the {@link HazelcastInstance}
 	 */
 	public HazelcastInstance getHazelcastInstance() {
+		return getHazelcastInstance(null);
+	}
+
+	/**
+	 * Get the {@link HazelcastInstance} with the specified {@link ClassLoader}.
+	 * @param classLoader the classloader to use for serialization
+	 * @return the {@link HazelcastInstance}
+	 */
+	public HazelcastInstance getHazelcastInstance(ClassLoader classLoader) {
+		if (classLoader != null) {
+			this.clientConfig.setClassLoader(classLoader);
+		}
 		if (StringUtils.hasText(this.clientConfig.getInstanceName())) {
 			return HazelcastClient.getOrCreateHazelcastClient(this.clientConfig);
 		}
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastInstanceFactory.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastInstanceFactory.java
index be66d2dffb4a..5506e8a02b50 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastInstanceFactory.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastInstanceFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -81,10 +81,22 @@ private static Config createConfig(URL configUrl) throws IOException {
 	}
 
 	/**
-	 * Get the {@link HazelcastInstance}.
+	 * Get the {@link HazelcastInstance} with the default {@link ClassLoader}.
 	 * @return the {@link HazelcastInstance}
 	 */
 	public HazelcastInstance getHazelcastInstance() {
+		return getHazelcastInstance(null);
+	}
+
+	/**
+	 * Get the {@link HazelcastInstance} with the specified {@link ClassLoader}.
+	 * @param classLoader the classloader to use for serialization
+	 * @return the {@link HazelcastInstance}
+	 */
+	public HazelcastInstance getHazelcastInstance(ClassLoader classLoader) {
+		if (classLoader != null) {
+			this.config.setClassLoader(classLoader);
+		}
 		if (StringUtils.hasText(this.config.getInstanceName())) {
 			return Hazelcast.getOrCreateHazelcastInstance(this.config);
 		}
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastServerConfiguration.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastServerConfiguration.java
index 0a552bb19d90..bc15a888374b 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastServerConfiguration.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastServerConfiguration.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -19,7 +19,6 @@
 import java.io.IOException;
 
 import com.hazelcast.config.Config;
-import com.hazelcast.core.Hazelcast;
 import com.hazelcast.core.HazelcastInstance;
 
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
@@ -28,6 +27,7 @@
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.io.Resource;
+import org.springframework.core.io.ResourceLoader;
 
 /**
  * Configuration for Hazelcast server.
@@ -47,12 +47,15 @@ class HazelcastServerConfiguration {
 	static class HazelcastServerConfigFileConfiguration {
 
 		@Bean
-		HazelcastInstance hazelcastInstance(HazelcastProperties properties) throws IOException {
-			Resource config = properties.resolveConfigLocation();
-			if (config != null) {
-				return new HazelcastInstanceFactory(config).getHazelcastInstance();
-			}
-			return Hazelcast.newHazelcastInstance();
+		HazelcastInstance hazelcastInstance(HazelcastProperties properties, ResourceLoader resourceLoader)
+				throws IOException {
+			return createHazelcastInstanceFactory(properties.resolveConfigLocation())
+					.getHazelcastInstance(resourceLoader.getClassLoader());
+		}
+
+		private HazelcastInstanceFactory createHazelcastInstanceFactory(Resource config) throws IOException {
+			return (config != null) ? new HazelcastInstanceFactory(config)
+					: new HazelcastInstanceFactory(Config.load());
 		}
 
 	}
@@ -63,6 +66,7 @@ static class HazelcastServerConfigConfiguration {
 
 		@Bean
 		HazelcastInstance hazelcastInstance(Config config) {
+			// TODO should we replace the ClassLoader here?
 			return new HazelcastInstanceFactory(config).getHazelcastInstance();
 		}