diff --git a/src/main/kotlin/org/mosad/thecitadelofricks/DataTypes.kt b/src/main/kotlin/org/mosad/thecitadelofricks/DataTypes.kt
index 41d45da..69e72b5 100644
--- a/src/main/kotlin/org/mosad/thecitadelofricks/DataTypes.kt
+++ b/src/main/kotlin/org/mosad/thecitadelofricks/DataTypes.kt
@@ -31,7 +31,7 @@ data class Course(val courseName: String, val courseLink: String)
 
 data class CoursesMeta(val updateTime: Long = 0, val totalCourses: Int = 0)
 
-data class CoursesList(val meta: CoursesMeta = CoursesMeta(), val courses: HashMap<String, Course> = HashMap())
+data class CoursesList(val meta: CoursesMeta = CoursesMeta(), val courses: SortedMap<String, Course>)
 data class CoursesListRet(val meta: CoursesMeta = CoursesMeta(), val courses: ArrayList<Course> = ArrayList())
 
 // data classes for the Mensa part
diff --git a/src/main/kotlin/org/mosad/thecitadelofricks/controller/CacheController.kt b/src/main/kotlin/org/mosad/thecitadelofricks/controller/CacheController.kt
index e0675ed..9c2ff53 100644
--- a/src/main/kotlin/org/mosad/thecitadelofricks/controller/CacheController.kt
+++ b/src/main/kotlin/org/mosad/thecitadelofricks/controller/CacheController.kt
@@ -49,7 +49,7 @@ class CacheController {
     companion object{
         private val logger: Logger = LoggerFactory.getLogger(CacheController::class.java)
 
-        var courseList = CoursesList()
+        var courseList = CoursesList(CoursesMeta(), sortedMapOf())
         var mensaMenu = MensaMenu(MensaMeta(0,""), MensaWeek(), MensaWeek())
         var timetableList = HashMap<String, TimetableCourseWeek>() // this list contains all timetables
 
@@ -137,7 +137,7 @@ class CacheController {
          */
         private fun asyncUpdateCourseList() = GlobalScope.launch {
             CourseListParser().getCourseLinks(StartupController.courseListURL)?.let {
-                courseList = CoursesList(CoursesMeta(System.currentTimeMillis() / 1000, it.size), it)
+                courseList = CoursesList(CoursesMeta(System.currentTimeMillis() / 1000, it.size), it.toSortedMap())
             }
 
             // TODO just for testing