diff --git a/src/main/java/device/usbPlayer/UsbPlayer.java b/src/main/java/device/usbPlayer/UsbPlayer.java
index b3ea2a8..992ba76 100644
--- a/src/main/java/device/usbPlayer/UsbPlayer.java
+++ b/src/main/java/device/usbPlayer/UsbPlayer.java
@@ -76,7 +76,7 @@ public class UsbPlayer implements Device {
 
         for (int i = 0; i < Playlist.size(); i++) {
             song = Playlist.get(i).substring(Playlist.get(i).length() - 4);
-            if (song.equals(".mp3") | song.equals(".mp4")| song.equals(".m4a")| song.equals(".wav")| song.equals(".wma") ) {
+            if (song.equals(".mp3") | song.equals(".mp4")| song.equals(".m4a")| song.equals(".wav")| song.equals(".wma")| song.equals(".aac") ) {
                 flag = true;
             } else {
                 flag = false;
diff --git a/src/test/java/device/usbPlayer/UsbPlayerTest.java b/src/test/java/device/usbPlayer/UsbPlayerTest.java
index d038d60..1c8ae91 100644
--- a/src/test/java/device/usbPlayer/UsbPlayerTest.java
+++ b/src/test/java/device/usbPlayer/UsbPlayerTest.java
@@ -282,12 +282,21 @@ class UsbPlayerTest {
         Pl3.add("Musik 02.wma");
         Pl3.add("Musik 03.wma");
         up5.setPlaylist(Pl3);
+        //aac
+        UsbPlayer up6 = new UsbPlayer();
+        ArrayList<String> Pl4 = new ArrayList<String>();
+        Pl4.add("Musik 01.aac");
+        Pl4.add("Musik 02.aac");
+        Pl4.add("Musik 03.aac");
+        up6.setPlaylist(Pl4);
+
         return Stream.of(
                 Arguments.of("Check if the Files are .mp3 ", up1.isAllAudio(), true),
                 Arguments.of("Check if the Files are .mp4 ", up2.isAllAudio(), true),
                 Arguments.of("Check if the Files are .m4a ", up3.isAllAudio(), true),
                 Arguments.of("Check if the Files are .wav ", up4.isAllAudio(), true),
-                Arguments.of("Check if the Files are .wma ", up5.isAllAudio(), true)
+                Arguments.of("Check if the Files are .wma ", up5.isAllAudio(), true),
+                Arguments.of("Check if the Files are .aac ", up6.isAllAudio(), true)
 
         );
     }