diff --git a/plugins/comment_paragraph/lib/ext/article.rb b/plugins/comment_paragraph/lib/ext/article.rb
index 978a72d..9ad813a 100644
--- a/plugins/comment_paragraph/lib/ext/article.rb
+++ b/plugins/comment_paragraph/lib/ext/article.rb
@@ -8,7 +8,7 @@ class Article
 
   def body_change_with_comments
     if body && body_changed? && !self.comments.empty?
-      paragraphs_with_comments = self.comments.where("'paragraph_id' IS NOT NULL")
+      paragraphs_with_comments = self.comments.where("paragraph_id IS NOT NULL")
       errors[:base] << (N_('You are unable to change the body of the article when paragraphs are commented')) unless (paragraphs_with_comments).empty?
     end
   end
--
libgit2 0.21.2