diff --git a/.idea/misc.xml b/.idea/misc.xml
index 3b63d6d..e63ec06 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -4,7 +4,7 @@
   <component name="FrameworkDetectionExcludesConfiguration">
     <file type="web" url="file://$PROJECT_DIR$" />
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="openjdk-21.0.1" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_X" default="true" project-jdk-name="openjdk-21.0.1" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
   <component name="ProjectType">
diff --git a/server/src/test/java/org/hyperskill/community/flashcards/TestFlashcardsApplication.java b/server/src/test/java/org/hyperskill/community/flashcards/TestFlashcardsApplication.java
index 93e36a7..fc4bff7 100644
--- a/server/src/test/java/org/hyperskill/community/flashcards/TestFlashcardsApplication.java
+++ b/server/src/test/java/org/hyperskill/community/flashcards/TestFlashcardsApplication.java
@@ -1,23 +1,13 @@
 package org.hyperskill.community.flashcards;
 
 import org.springframework.boot.SpringApplication;
-import org.springframework.boot.test.context.TestConfiguration;
-import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
-import org.springframework.context.annotation.Bean;
-import org.testcontainers.containers.MongoDBContainer;
-import org.testcontainers.utility.DockerImageName;
 
-@TestConfiguration(proxyBeanMethods = false)
 public class TestFlashcardsApplication {
 
-    @Bean
-    @ServiceConnection
-    MongoDBContainer mongoDbContainer() {
-        return new MongoDBContainer(DockerImageName.parse("mongo:latest"));
-    }
-
     public static void main(String[] args) {
-        SpringApplication.from(FlashcardsApplication::main).with(TestFlashcardsApplication.class).run(args);
+        SpringApplication
+                .from(FlashcardsApplication::main)
+                .with(TestFlashcardsApplication.class)
+                .run(args);
     }
-
 }
diff --git a/server/src/test/java/org/hyperskill/community/flashcards/TestMongoConfiguration.java b/server/src/test/java/org/hyperskill/community/flashcards/TestMongoConfiguration.java
new file mode 100644
index 0000000..dd88c85
--- /dev/null
+++ b/server/src/test/java/org/hyperskill/community/flashcards/TestMongoConfiguration.java
@@ -0,0 +1,20 @@
+package org.hyperskill.community.flashcards;
+
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
+import org.springframework.context.annotation.Bean;
+import org.testcontainers.containers.MongoDBContainer;
+
+import java.util.List;
+
+@TestConfiguration
+public class TestMongoConfiguration {
+
+    @Bean
+    @ServiceConnection
+    public MongoDBContainer mongoDBContainer() {
+        var container = new MongoDBContainer("mongo:latest");
+        container.setPortBindings(List.of("27017:27017"));
+        return container;
+    }
+}
diff --git a/server/src/test/java/org/hyperskill/community/flashcards/security/RegisterServerSecurityIT.java b/server/src/test/java/org/hyperskill/community/flashcards/security/RegisterServerSecurityIT.java
index a12b306..7fac298 100644
--- a/server/src/test/java/org/hyperskill/community/flashcards/security/RegisterServerSecurityIT.java
+++ b/server/src/test/java/org/hyperskill/community/flashcards/security/RegisterServerSecurityIT.java
@@ -1,53 +1,28 @@
 package org.hyperskill.community.flashcards.security;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import org.hyperskill.community.flashcards.TestMongoConfiguration;
 import org.hyperskill.community.flashcards.registration.UserDto;
-import org.junit.jupiter.api.AfterAll;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
 import org.springframework.http.MediaType;
-import org.springframework.test.context.aot.DisabledInAotMode;
 import org.springframework.test.web.servlet.MockMvc;
-import org.testcontainers.containers.MongoDBContainer;
-import org.testcontainers.junit.jupiter.Container;
-import org.testcontainers.junit.jupiter.Testcontainers;
-import org.testcontainers.utility.DockerImageName;
 
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
-@SpringBootTest
-@Testcontainers
+@SpringBootTest(classes = TestMongoConfiguration.class)
 @AutoConfigureMockMvc
-@Disabled // must fix test container connections...
-@DisabledInAotMode // bug in Spring 3.2 @MockBean does not work in AOT mode (https://github.com/spring-projects/spring-boot/issues/36997)
 class RegisterServerSecurityIT {
 
     @Autowired
     MockMvc mockMvc;
 
-    @Container
-    @ServiceConnection
-    static MongoDBContainer mongoDbContainer =  new MongoDBContainer(DockerImageName.parse("mongo:latest"));
-
     @Autowired
     ObjectMapper objectMapper;
 
-    @BeforeAll
-    static void setup() {
-        mongoDbContainer.start();
-    }
-
-    @AfterAll
-    static void tearDown() {
-        mongoDbContainer.stop();
-    }
-
     @Test
     void registerUnauthenticatedValidJson_AddsUser() throws Exception {
         mockMvc.perform(post("/api/register")