diff --git a/app/models/concerns/justifiable.rb b/app/models/concerns/justifiable.rb
index a6f4e8df49f..bd4af895427 100644
--- a/app/models/concerns/justifiable.rb
+++ b/app/models/concerns/justifiable.rb
@@ -18,7 +18,9 @@ module Justifiable
   private
 
   def strip_octothorpe
-    self.ticket_number = self.ticket_number.delete_prefix("#") unless self.ticket_number.nil?
+    unless ticket_number.is_a?(Integer)
+      self.ticket_number = self.ticket_number.delete_prefix("#") unless self.ticket_number.nil?
+    end
   end
 
   def enabled?
diff --git a/spec/models/concerns/justifiable_spec.rb b/spec/models/concerns/justifiable_spec.rb
index b023e56a6f0..2e68cd2bd48 100644
--- a/spec/models/concerns/justifiable_spec.rb
+++ b/spec/models/concerns/justifiable_spec.rb
@@ -26,7 +26,7 @@
 
       record.assign_attributes(attributes)
       expect(record).not_to be_valid
-      expect(record.errors[:ticket_number]).to contain_exactly("can't be blank", "is not a number")
+      expect(record.errors[:ticket_number]).to contain_exactly("can't be blank", "may begin with an # and otherwise contain only numbers.")
       expect(record.ticket_url).to be_nil
     end