diff --git a/app/models/issue_query.rb b/app/models/issue_query.rb
index eb7684cc2..ec3d5ec62 100644
--- a/app/models/issue_query.rb
+++ b/app/models/issue_query.rb
@@ -575,8 +575,9 @@ class IssueQuery < Query
         end
       sw = operator == "!" ? 'NOT' : ''
       nl = operator == "!" ? "#{Issue.table_name}.assigned_to_id IS NULL OR" : ''
-      "(#{nl} #{Issue.table_name}.assigned_to_id #{sw} IN (SELECT DISTINCT #{Member.table_name}.user_id FROM #{Member.table_name}, #{MemberRole.table_name}" +
-        " WHERE #{Member.table_name}.project_id = #{Issue.table_name}.project_id AND #{Member.table_name}.id = #{MemberRole.table_name}.member_id AND #{role_cond}))"
+      "(#{nl} (#{Issue.table_name}.assigned_to_id, #{Issue.table_name}.project_id) #{sw} IN (" +
+        " SELECT DISTINCT #{Member.table_name}.user_id, #{Member.table_name}.project_id FROM #{Member.table_name}, #{MemberRole.table_name}" +
+        " WHERE #{Member.table_name}.id = #{MemberRole.table_name}.member_id AND #{role_cond}))"
     end
   end