diff --git a/aws-serverless-java-container-springboot3/src/main/java/com/amazonaws/serverless/proxy/spring/SpringBootLambdaContainerHandler.java b/aws-serverless-java-container-springboot3/src/main/java/com/amazonaws/serverless/proxy/spring/SpringBootLambdaContainerHandler.java
index 6b3dd5ca2..45bf28efe 100644
--- a/aws-serverless-java-container-springboot3/src/main/java/com/amazonaws/serverless/proxy/spring/SpringBootLambdaContainerHandler.java
+++ b/aws-serverless-java-container-springboot3/src/main/java/com/amazonaws/serverless/proxy/spring/SpringBootLambdaContainerHandler.java
@@ -18,7 +18,7 @@
 import org.slf4j.LoggerFactory;
 import org.springframework.boot.WebApplicationType;
 import org.springframework.boot.builder.SpringApplicationBuilder;
-import org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext;
+import org.springframework.web.context.ConfigurableWebApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
 
 import com.amazonaws.serverless.exceptions.ContainerInitializationException;
@@ -184,20 +184,26 @@ protected void handleRequest(HttpServletRequest containerRequest, AwsHttpServlet
         Timer.stop("SPRINGBOOT2_HANDLE_REQUEST");
     }
 
+    SpringApplicationBuilder getSpringApplicationBuilder(Class<?>... sources) {
+        return new SpringApplicationBuilder(sources);
+    }
 
     @Override
     public void initialize()
             throws ContainerInitializationException {
         Timer.start("SPRINGBOOT2_COLD_START");
 
-        SpringApplicationBuilder builder = new SpringApplicationBuilder(getEmbeddedContainerClasses())
+        SpringApplicationBuilder builder = getSpringApplicationBuilder(getEmbeddedContainerClasses())
                 .web(springWebApplicationType); // .REACTIVE, .SERVLET
+        if(springBootInitializer != null) {
+            builder.main(springBootInitializer);
+        }
         if (springProfiles != null) {
             builder.profiles(springProfiles);
         }
         applicationContext = builder.run();
         if (springWebApplicationType == WebApplicationType.SERVLET) {
-            ((AnnotationConfigServletWebServerApplicationContext)applicationContext).setServletContext(getServletContext());
+            ((ConfigurableWebApplicationContext)applicationContext).setServletContext(getServletContext());
             AwsServletRegistration reg = (AwsServletRegistration)getServletContext().getServletRegistration(DISPATCHER_SERVLET_REGISTRATION_NAME);
             if (reg != null) {
                 reg.setLoadOnStartup(1);
diff --git a/aws-serverless-java-container-springboot3/src/test/java/com/amazonaws/serverless/proxy/spring/SpringBootLambdaContainerHandlerTest.java b/aws-serverless-java-container-springboot3/src/test/java/com/amazonaws/serverless/proxy/spring/SpringBootLambdaContainerHandlerTest.java
new file mode 100644
index 000000000..871a751bb
--- /dev/null
+++ b/aws-serverless-java-container-springboot3/src/test/java/com/amazonaws/serverless/proxy/spring/SpringBootLambdaContainerHandlerTest.java
@@ -0,0 +1,76 @@
+package com.amazonaws.serverless.proxy.spring;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import com.amazonaws.serverless.exceptions.ContainerInitializationException;
+import com.amazonaws.serverless.proxy.AwsProxyExceptionHandler;
+import com.amazonaws.serverless.proxy.AwsProxySecurityContextWriter;
+import com.amazonaws.serverless.proxy.InitializationWrapper;
+import com.amazonaws.serverless.proxy.internal.servlet.AwsProxyHttpServletRequestReader;
+import com.amazonaws.serverless.proxy.internal.servlet.AwsProxyHttpServletResponseWriter;
+import com.amazonaws.serverless.proxy.model.AwsProxyRequest;
+import com.amazonaws.serverless.proxy.model.AwsProxyResponse;
+import com.amazonaws.serverless.proxy.spring.servletapp.ServletApplication;
+import com.amazonaws.serverless.proxy.spring.webfluxapp.WebFluxTestApplication;
+import java.util.Collection;
+import java.util.List;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.mockito.Mockito;
+import org.springframework.boot.WebApplicationType;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+
+class SpringBootLambdaContainerHandlerTest {
+
+    SpringBootLambdaContainerHandler<AwsProxyRequest, AwsProxyResponse> handler;
+    SpringApplicationBuilder springApplicationBuilder;
+
+    public static Collection<TestData> data() {
+        return List.of(new TestData(WebApplicationType.SERVLET, ServletApplication.class),
+            new TestData(WebApplicationType.REACTIVE, WebFluxTestApplication.class));
+    }
+
+    private void initSpringBootLambdaContainerHandlerTest(Class<?> springBootInitializer,
+        WebApplicationType applicationType) {
+        handler = Mockito.spy(new SpringBootLambdaContainerHandler<>(AwsProxyRequest.class,
+            AwsProxyResponse.class,
+            new AwsProxyHttpServletRequestReader(),
+            new AwsProxyHttpServletResponseWriter(),
+            new AwsProxySecurityContextWriter(),
+            new AwsProxyExceptionHandler(),
+            springBootInitializer,
+            new InitializationWrapper(),
+            applicationType));
+
+        doAnswer(d -> {
+            springApplicationBuilder = ((SpringApplicationBuilder) Mockito.spy(d.callRealMethod()));
+            return springApplicationBuilder;
+        }).when(handler).getSpringApplicationBuilder(any(Class[].class));
+    }
+
+    @ParameterizedTest
+    @MethodSource("data")
+    void initialize_withSpringBootInitializer(TestData data) throws ContainerInitializationException {
+        initSpringBootLambdaContainerHandlerTest(data.springBootApplication(), data.applicationType());
+        handler.initialize();
+
+        verify(springApplicationBuilder, times(1)).main(data.springBootApplication());
+    }
+
+    @ParameterizedTest
+    @EnumSource(WebApplicationType.class)
+    void initialize_withoutSpringBootInitializer(WebApplicationType webApplicationType) {
+        initSpringBootLambdaContainerHandlerTest(null, webApplicationType);
+        assertThrows(IllegalArgumentException.class, handler::initialize, "Source must not be null");
+
+        verify(springApplicationBuilder, never()).main(any());
+    }
+
+    record TestData(WebApplicationType applicationType, Class<?> springBootApplication) {}
+}
\ No newline at end of file