diff --git a/aesop/ovvpfile.py b/aesop/ovvpfile.py
index a9d67c43..4d58af35 100644
--- a/aesop/ovvpfile.py
+++ b/aesop/ovvpfile.py
@@ -14,10 +14,10 @@ class OvvpFile:
 	def to_lines(self):
 		# header
 		for hk in sorted(self.headers.keys()):
-			yield '%s\t%s\n' % (hk, self.headers[hk])
+			yield f'{hk}\t{self.headers[hk]}\n'
 		yield '\n'
 		# columns
-		yield '\t'.join([c for c in self.columns]) + '\n'
+		yield '\t'.join(self.columns) + '\n'
 		# rows
 		for r in self.rows:
 			yield '\t'.join([force_text(r[c]) for c in self.columns]) + '\n'