diff --git a/app/models/journal_detail.rb b/app/models/journal_detail.rb
index 831f953ae..58239006b 100644
--- a/app/models/journal_detail.rb
+++ b/app/models/journal_detail.rb
@@ -19,7 +19,7 @@ class JournalDetail < ActiveRecord::Base
   belongs_to :journal
   
   def before_save
-    self.value = value[0..254] if value
-    self.old_value = old_value[0..254] if old_value
+    self.value = value[0..254] if value && value.is_a?(String)
+    self.old_value = old_value[0..254] if old_value && old_value.is_a?(String)
   end
 end