diff --git a/app/controllers/issues_controller.rb b/app/controllers/issues_controller.rb
index 7b3684c85..6433acc5f 100644
--- a/app/controllers/issues_controller.rb
+++ b/app/controllers/issues_controller.rb
@@ -287,9 +287,9 @@ private
       sort_update(@query.sortable_columns, 'issues_index_sort')
       limit = 500
       issue_ids = @query.issue_ids(:order => sort_clause, :limit => (limit + 1))
-      if (idx = issue_ids.index(@issue.id.to_s)) && idx < limit
-        @prev_issue_id = issue_ids[idx - 1].to_i if idx > 0
-        @next_issue_id = issue_ids[idx + 1].to_i if idx < (issue_ids.size - 1)
+      if (idx = issue_ids.index(@issue.id)) && idx < limit
+        @prev_issue_id = issue_ids[idx - 1] if idx > 0
+        @next_issue_id = issue_ids[idx + 1] if idx < (issue_ids.size - 1)
       end
     end
   end
diff --git a/lib/redmine/core_ext/active_record.rb b/lib/redmine/core_ext/active_record.rb
index ba57b639a..f881f90a5 100644
--- a/lib/redmine/core_ext/active_record.rb
+++ b/lib/redmine/core_ext/active_record.rb
@@ -27,7 +27,7 @@ module ActiveRecord
       def find_ids_with_associations(options = {})
         catch :invalid_query do
           join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(self, merge_includes(scope(:find, :include), options[:include]), options[:joins])
-          return connection.select_values(construct_ids_finder_sql_with_included_associations(options, join_dependency))
+          return connection.select_values(construct_ids_finder_sql_with_included_associations(options, join_dependency)).map(&:to_i)
         end
         []
       end
diff --git a/test/unit/query_test.rb b/test/unit/query_test.rb
index 6fc0bd2e8..78499bfd0 100644
--- a/test/unit/query_test.rb
+++ b/test/unit/query_test.rb
@@ -616,7 +616,7 @@ class QueryTest < ActiveSupport::TestCase
     q = Query.new(:name => '_')
     order = "issues.subject, issues.id"
     issues = q.issues(:order => order)
-    assert_equal issues.map(&:id).map(&:to_s), q.issue_ids(:order => order)
+    assert_equal issues.map(&:id), q.issue_ids(:order => order)
   end
 
   def test_label_for