diff --git a/backend/app/controllers/wiki_pages_controller.rb b/backend/app/controllers/wiki_pages_controller.rb
index fb465a3..c4dedf0 100644
--- a/backend/app/controllers/wiki_pages_controller.rb
+++ b/backend/app/controllers/wiki_pages_controller.rb
@@ -49,7 +49,7 @@ class WikiPagesController < ApplicationController
       case change.action
       when ?=
         { type: 'context', content: change.old_element }
-      when ?|
+      when ?!
         [{ type: 'removed', content: change.old_element },
          { type: 'added', content: change.new_element }]
       when ?+
@@ -98,13 +98,18 @@ class WikiPagesController < ApplicationController
     return head :unprocessable_entity if title.blank? || body.blank?
 
     page = WikiPage.find(params[:id])
+    base_revision_id = page.current_revision.id
 
     if params[:title].present? && params[:title].strip != page.title
       return head :unprocessable_entity
     end
 
     message = params[:message].presence
-    Wiki::Commit.content!(page:, body:, created_user: current_user, message:)
+    Wiki::Commit.content!(page:,
+                          body:,
+                          created_user: current_user,
+                          message:,
+                          base_revision_id:)
 
     head :ok
   end
diff --git a/frontend/src/pages/wiki/WikiDiffPage.tsx b/frontend/src/pages/wiki/WikiDiffPage.tsx
index 85a62f0..e99033b 100644
--- a/frontend/src/pages/wiki/WikiDiffPage.tsx
+++ b/frontend/src/pages/wiki/WikiDiffPage.tsx
@@ -40,10 +40,10 @@ export default () => {
 	  {diff
 	   ? (
 	      diff.diff.map (d => (
-		  <span className={cn (d.type === 'added' && 'bg-green-200 dark:bg-green-800',
-				       d.type === 'removed' && 'bg-red-200 dark:bg-red-800')}>
-		    {d.content == '\n' ? <br/> : d.content}
-		  </span>)))
+		  <p className={cn (d.type === 'added' && 'bg-green-200 dark:bg-green-800',
+				    d.type === 'removed' && 'bg-red-200 dark:bg-red-800')}>
+		    {d.content}
+		  </p>)))
 	   : 'Loading...'}
 	</div>
       </MainArea>)