diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/project/GetAccess.java b/gerrit-server/src/main/java/com/google/gerrit/server/project/GetAccess.java
index e8252b4..589d642 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/project/GetAccess.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/project/GetAccess.java
@@ -307,7 +307,7 @@
         }
         AccountGroup.UUID group = r.getGroup().getUUID();
         if (group != null) {
-          pInfo.rules.put(group.get(), info);
+          pInfo.rules.putIfAbsent(group.get(), info); // First entry for the group wins
           loadGroup(groups, group);
         }
       }