diff --git a/modules/common/src/main/java/org/dcache/auth/AbstractUidPrincipal.java b/modules/common/src/main/java/org/dcache/auth/AbstractUidPrincipal.java
index 33a7279de98..7d4d78b87c9 100644
--- a/modules/common/src/main/java/org/dcache/auth/AbstractUidPrincipal.java
+++ b/modules/common/src/main/java/org/dcache/auth/AbstractUidPrincipal.java
@@ -101,6 +101,11 @@ public boolean equals(Object other) {
         if (this == other) {
             return true;
         }
+
+        if (other == null) {
+            return false;
+        }
+
         if (!(this.getClass().equals(other.getClass()))) {
             return false;
         }