diff --git a/Mage/src/main/java/mage/watchers/Watcher.java b/Mage/src/main/java/mage/watchers/Watcher.java
index a091867b295..d9e007666a7 100644
--- a/Mage/src/main/java/mage/watchers/Watcher.java
+++ b/Mage/src/main/java/mage/watchers/Watcher.java
@@ -143,7 +143,7 @@ public abstract class Watcher implements Serializable {
                                 Cards list = e.getValue().copy();
                                 target.put(e.getKey(), list);
                             }
-                        } else if (Arrays.stream(((Class) valueType).getInterfaces()).anyMatch(c -> c.equals(Copyable.class))) {
+                        } else if (valueType instanceof Class &&  Arrays.stream(((Class) valueType).getInterfaces()).anyMatch(c -> c.equals(Copyable.class))) {
                             Map<Object, Copyable> source = (Map<Object, Copyable>) field.get(this);
                             Map<Object, Copyable> target = (Map<Object, Copyable>) field.get(watcher);
                             target.clear();