1 files changed, 5 insertions, 3 deletions
diff --git a/app/models/principal.rb b/app/models/principal.rb
index e62b5f320..4cce97e26 100644
--- a/app/models/principal.rb
+++ b/app/models/principal.rb
@@ -151,9 +151,11 @@ class Principal < ActiveRecord::Base
   end
 
   def <=>(principal)
-    if principal.nil?
-      -1
-    elsif self.class.name == principal.class.name
+    # avoid an error when sorting members without roles (#10053)
+    return -1 if principal.nil?
+    return nil unless principal.is_a?(Principal)
+
+    if self.class.name == principal.class.name
       self.to_s.casecmp(principal.to_s)
     else
       # groups after users