diff --git a/frappe/core/doctype/comment/comment.py b/frappe/core/doctype/comment/comment.py
index 192b949e6d..a5e5a1a028 100644
--- a/frappe/core/doctype/comment/comment.py
+++ b/frappe/core/doctype/comment/comment.py
@@ -102,7 +102,7 @@ class Comment(Document):
 
 def on_doctype_update():
 	frappe.db.add_index("Comment", ["reference_doctype", "reference_name"])
-	frappe.db.add_index("Communication", ["link_doctype", "link_name"])
+	frappe.db.add_index("Comment", ["link_doctype", "link_name"])
 
 
 def update_comment_in_doc(doc):