diff --git a/app/models/project.rb b/app/models/project.rb
index be46d6189..03ada035c 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -132,7 +132,7 @@ class Project < ActiveRecord::Base
   
   # Users issues can be assigned to
   def assignable_users
-    members.select {|m| m.role.assignable?}.collect {|m| m.user}
+    members.select {|m| m.role.assignable?}.collect {|m| m.user}.sort
   end
   
   # Returns the mail adresses of users that should be always notified on project events
diff --git a/app/models/query.rb b/app/models/query.rb
index 4cc5a63a5..4133abd88 100644
--- a/app/models/query.rb
+++ b/app/models/query.rb
@@ -147,7 +147,7 @@ class Query < ActiveRecord::Base
     user_values = []
     user_values << ["<< #{l(:label_me)} >>", "me"] if executed_by
     if project
-      user_values += project.users.collect{|s| [s.name, s.id.to_s] }
+      user_values += project.users.sort.collect{|s| [s.name, s.id.to_s] }
     elsif executed_by
       # members of the user's projects
       user_values += executed_by.projects.collect(&:users).flatten.uniq.sort.collect{|s| [s.name, s.id.to_s] }
diff --git a/app/models/user.rb b/app/models/user.rb
index 37512fda0..737a8cc8e 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -163,7 +163,7 @@ class User < ActiveRecord::Base
   end
 
   def <=>(user)
-    lastname == user.lastname ? firstname <=> user.firstname : lastname <=> user.lastname
+    user.nil? ? -1 : (lastname == user.lastname ? firstname <=> user.firstname : lastname <=> user.lastname)
   end
   
   def to_s