diff --git a/examples/apply-function/myfunctions.py b/examples/apply-function/myfunctions.py
index eead61a..e0f2a50 100644
--- a/examples/apply-function/myfunctions.py
+++ b/examples/apply-function/myfunctions.py
@@ -14,6 +14,6 @@ def hash_starts_numeric(records):
     their sha-1 hash.
     """
     for record in records:
-        seq_hash = hashlib.sha1(str(record.seq)).hexdigest()
+        seq_hash = hashlib.sha1(str(record.seq).encode('utf-8')).hexdigest()
         if seq_hash[0].isdigit():
             yield record