diff --git a/mhcflurry/allele_encoding_transforms.py b/mhcflurry/allele_encoding_transforms.py
index 018d831e62a195bdfd9fec7b6cf9b6e927922258..236066ebc527dea4c84abd52d34abf9017f6e9d1 100644
--- a/mhcflurry/allele_encoding_transforms.py
+++ b/mhcflurry/allele_encoding_transforms.py
@@ -27,6 +27,7 @@ class AlleleEncodingTransform(object):
         ----------
         fit : string to array
         """
+        pass
 
 
 class PCATransform(AlleleEncodingTransform):