diff --git a/files/classes/comment.py b/files/classes/comment.py
index d973a87874..b81a3a54c6 100644
--- a/files/classes/comment.py
+++ b/files/classes/comment.py
@@ -370,7 +370,7 @@ class Comment(Base):
 
 
 		if self.author.sig_html and not self.ghost and (self.author_id == MOOSE_ID or not (v and v.sigs_disabled)):
-			body += "<hr>{self.author.sig_html}"
+			body += f"<hr>{self.author.sig_html}"
 
 		return body
 
diff --git a/files/classes/submission.py b/files/classes/submission.py
index 9dd94b61b2..2658df688d 100644
--- a/files/classes/submission.py
+++ b/files/classes/submission.py
@@ -383,7 +383,7 @@ class Submission(Base):
 				g.db.commit()
 
 		if self.author.sig_html and not self.ghost and (self.author_id == MOOSE_ID or not (v and v.sigs_disabled)):
-			body += "<hr>{self.author.sig_html}"
+			body += f"<hr>{self.author.sig_html}"
 
 		return body