diff --git a/src/main/java/nl/tudelft/jpacman/level/Level.java b/src/main/java/nl/tudelft/jpacman/level/Level.java
index 89fbf2072..a5c76147a 100644
--- a/src/main/java/nl/tudelft/jpacman/level/Level.java
+++ b/src/main/java/nl/tudelft/jpacman/level/Level.java
@@ -263,6 +263,8 @@ public boolean isInProgress() {
      * Updates the observers about the state of this level.
      */
     private void updateObservers() {
+        Iterable<LevelObserver> observers = new ArrayList<>(this.observers);
+
         if (!isAnyPlayerAlive()) {
             for (LevelObserver observer : observers) {
                 observer.levelLost();