diff --git a/observer/src/test/java/com/iluwatar/observer/AppTest.java b/observer/src/test/java/com/iluwatar/observer/AppTest.java
index 38d5c0503..65976626d 100644
--- a/observer/src/test/java/com/iluwatar/observer/AppTest.java
+++ b/observer/src/test/java/com/iluwatar/observer/AppTest.java
@@ -11,9 +11,9 @@ import com.iluwatar.observer.App;
  */
 public class AppTest {
 
-	@Test
-	public void test() {
-		String[] args = {};
-		App.main(args);
-	}
+  @Test
+  public void test() {
+    String[] args = {};
+    App.main(args);
+  }
 }