diff --git a/composer.json b/composer.json
index 70f2fe9..c4d47b9 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
         }
     ],
     "require": {
-        "php": "^7.3|^8.0",
+        "php": ">=7.3",
         "ext-curl": "*",
         "ext-json" : "*",
         "league/oauth2-client": "~2.3",
diff --git a/src/Entity/Book.php b/src/Entity/Book.php
index 0725abb..4a41639 100644
--- a/src/Entity/Book.php
+++ b/src/Entity/Book.php
@@ -15,6 +15,7 @@ abstract class Book extends Entity
     const TYPE_PDF = 'pdf';
     const TYPE_VIDEO = 'video';
     const TYPE_AUDIOTALK = 'audioTalk';
+    const TYPE_CLASSROOM = 'classroom';
 
     const FORMAT_PDF = 'pdf';
     const FORMAT_EPUB = 'epub';
diff --git a/src/Entity/ClassroomBook.php b/src/Entity/ClassroomBook.php
new file mode 100644
index 0000000..77f60f5
--- /dev/null
+++ b/src/Entity/ClassroomBook.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace Bookboon\Api\Entity;
+
+class ClassroomBook extends Book
+{
+    const _OWN_TYPE = Book::TYPE_CLASSROOM;
+}
\ No newline at end of file