diff --git a/src/main/java/horse/wtf/nzyme/MockNzyme.java b/src/main/java/horse/wtf/nzyme/MockNzyme.java
index 0fce91696..f97193808 100644
--- a/src/main/java/horse/wtf/nzyme/MockNzyme.java
+++ b/src/main/java/horse/wtf/nzyme/MockNzyme.java
@@ -196,7 +196,7 @@ public ContactManager getContactManager() {
 
     @Override
     public List<String> getIgnoredFingerprints() {
-        return null;
+        return Collections.emptyList();
     }
 
     @Override