diff --git a/app/models/publication.rb b/app/models/publication.rb
index 8170b3e0..62448039 100644
--- a/app/models/publication.rb
+++ b/app/models/publication.rb
@@ -36,22 +36,22 @@ class Publication < ApplicationRecord
   scope :unpublished, -> { where(published_at: nil) }
 
   scope :with_id, ->(id) do
-    nn, vv = id.to_s.split('@')
+    number_or_uuid, version = id.to_s.split('@')
+    number = Integer(number_or_uuid) rescue nil
 
     join_rel = joins(:publication_group)
-    or_rel = join_rel.where(publication_group: { uuid: nn }).or(
-      join_rel.where(publication_group: { number: nn })
-    )
+    or_rel = join_rel.where(publication_group: { uuid: number_or_uuid })
+    or_rel = or_rel.or(join_rel.where(publication_group: { number: number })) unless number.nil?
 
-    rel = case vv
+    rel = case version
     when NilClass
-      join_rel.where(uuid: nn).or(or_rel.published)
+      join_rel.where(uuid: number_or_uuid).or(or_rel.published)
     when 'draft', 'd'
       or_rel.unpublished
     when 'latest'
       or_rel.chainable_latest
     else
-      or_rel.where(version: vv)
+      or_rel.where(version: version)
     end
 
     rel.order('"publication_group"."number" ASC').order(version: :desc)
diff --git a/lib/publishable/active_record.rb b/lib/publishable/active_record.rb
index 4edc13ec..26bede66 100644
--- a/lib/publishable/active_record.rb
+++ b/lib/publishable/active_record.rb
@@ -26,22 +26,23 @@ def publishable(options = {})
           scope :unpublished, -> { joins(:publication).where(publication: { published_at: nil }) }
 
           scope :with_id, ->(id) do
-            nn, vv = id.to_s.split('@')
+            number_or_uuid, version = id.to_s.split('@')
+            number = Integer(number_or_uuid) rescue nil
 
             join_rel = joins(publication: :publication_group)
-            or_rel = join_rel.where(publication_group: { uuid: nn }).or(
-              join_rel.where(publication_group: { number: nn })
-            )
+            or_rel = join_rel.where(publication_group: { uuid: number_or_uuid })
+            or_rel = or_rel.or(join_rel.where(publication_group: { number: number })) \
+              unless number.nil?
 
-            rel = case vv
+            rel = case version
             when NilClass
-              join_rel.where(publication: { uuid: nn }).or(or_rel.published)
+              join_rel.where(publication: { uuid: number_or_uuid }).or(or_rel.published)
             when 'draft', 'd'
               or_rel.unpublished
             when 'latest'
               or_rel.chainable_latest
             else
-              or_rel.where(publication: { version: vv })
+              or_rel.where(publication: { version: version })
             end
 
             rel.order('"publication_group"."number" ASC').order('"publication"."version" DESC')
diff --git a/spec/models/exercise_spec.rb b/spec/models/exercise_spec.rb
index db034d2e..797b77fa 100644
--- a/spec/models/exercise_spec.rb
+++ b/spec/models/exercise_spec.rb
@@ -1,7 +1,6 @@
 require 'rails_helper'
 
 RSpec.describe Exercise, type: :model do
-
   subject(:exercise) { FactoryBot.create :exercise }
 
   it { is_expected.to have_many(:questions).dependent(:destroy).autosave(true) }
@@ -74,5 +73,4 @@
       expect(exercise.can_view_solutions?(user)).to eq false
     end
   end
-
 end
diff --git a/spec/models/publication_spec.rb b/spec/models/publication_spec.rb
index 00738577..f759561f 100644
--- a/spec/models/publication_spec.rb
+++ b/spec/models/publication_spec.rb
@@ -1,4 +1,4 @@
-require "rails_helper"
+require 'rails_helper'
 
 RSpec.describe Publication, type: :model do
   subject(:publication) { FactoryBot.create :publication }