diff --git a/libs/micronaut-facebook-sdk/src/main/java/com/agorapulse/micronaut/facebooksdk/AbstractFacebookApplicationConfiguration.java b/libs/micronaut-facebook-sdk/src/main/java/com/agorapulse/micronaut/facebooksdk/AbstractFacebookApplicationConfiguration.java
index 5dbd188..c37a066 100644
--- a/libs/micronaut-facebook-sdk/src/main/java/com/agorapulse/micronaut/facebooksdk/AbstractFacebookApplicationConfiguration.java
+++ b/libs/micronaut-facebook-sdk/src/main/java/com/agorapulse/micronaut/facebooksdk/AbstractFacebookApplicationConfiguration.java
@@ -21,7 +21,6 @@
 
 import jakarta.validation.constraints.Min;
 import jakarta.validation.constraints.NotBlank;
-import jakarta.validation.constraints.NotNull;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -31,7 +30,7 @@ public abstract class AbstractFacebookApplicationConfiguration {
     @NotBlank
     private String secret;
 
-    @NotNull @Min(1)
+    @Min(1)
     private Long id;
 
     private String version = Version.LATEST.getUrlElement();
diff --git a/libs/micronaut-facebook-sdk/src/test/groovy/com/agorapulse/micronaut/facebooksdk/FacebookApplicationConfigurationSpec.groovy b/libs/micronaut-facebook-sdk/src/test/groovy/com/agorapulse/micronaut/facebooksdk/FacebookApplicationConfigurationSpec.groovy
index e8d4000..dda0e03 100644
--- a/libs/micronaut-facebook-sdk/src/test/groovy/com/agorapulse/micronaut/facebooksdk/FacebookApplicationConfigurationSpec.groovy
+++ b/libs/micronaut-facebook-sdk/src/test/groovy/com/agorapulse/micronaut/facebooksdk/FacebookApplicationConfigurationSpec.groovy
@@ -28,23 +28,33 @@ import spock.lang.Specification
 @CompileDynamic
 class FacebookApplicationConfigurationSpec extends Specification {
 
-    FacebookApplication application
-
     @AutoCleanup ApplicationContext context
 
-    void setup() {
-        context = ApplicationContext.builder(
-            'facebook.sdk.app.api-version': 'v16.0',
-            'facebook.sdk.app.id': '1234567890',
-            'facebook.sdk.app.secret': 'secret'
-        ).build()
-        context.start()
+    void 'application version is converted'() {
+        given:
+            context = ApplicationContext.builder(
+                    'facebook.sdk.app.api-version': 'v16.0',
+                    'facebook.sdk.app.id': '1234567890',
+                    'facebook.sdk.app.secret': 'secret'
+            ).build()
+            context.start()
 
-        application = context.getBean(FacebookApplication)
+            FacebookApplication application = context.getBean(FacebookApplication)
+            FacebookClient client = application.createClient()
+        expect:
+            client instanceof DefaultFacebookClient
+            client.apiVersion == Version.VERSION_16_0
     }
 
-    void 'application version is converted'() {
+    void 'app id is optional'() {
         given:
+            context = ApplicationContext.builder(
+                    'facebook.sdk.app.api-version': 'v16.0',
+                    'facebook.sdk.app.secret': 'secret'
+            ).build()
+            context.start()
+
+            FacebookApplication application = context.getBean(FacebookApplication)
             FacebookClient client = application.createClient()
         expect:
             client instanceof DefaultFacebookClient