diff --git a/join-metadata-and-clades.py b/join-metadata-and-clades.py
index 0a29e4c..169b069 100755
--- a/join-metadata-and-clades.py
+++ b/join-metadata-and-clades.py
@@ -4,8 +4,6 @@
 import sys
 import pandas as pd
 
-VALUE_MISSING_DATA = '?'
-
 def parse_args():
     parser = argparse.ArgumentParser(
         description="Joins metadata file with Nextclade clade output",