diff --git a/downloads-generation/models_class1_pan_refined/hyperparameters.yaml b/downloads-generation/models_class1_pan_refined/hyperparameters.yaml
index f165687660c9d36d217d32422a582d41faab0cf1..0501a4e176efc82555c3e6589c42eaaba16b2b9f 100644
--- a/downloads-generation/models_class1_pan_refined/hyperparameters.yaml
+++ b/downloads-generation/models_class1_pan_refined/hyperparameters.yaml
@@ -1,7 +1,7 @@
 #########################
 # Batch generation
 #########################
-batch_generator: simple
+batch_generator: multiallelic_mass_spec
 batch_generator_validation_split: 0.1
 batch_generator_batch_size: 1024
 batch_generator_affinity_fraction: 0.5
diff --git a/mhcflurry/downloads.yml b/mhcflurry/downloads.yml
index 789efcd20bddf88d85b32975e8176bc0c29fbedf..841372dc8e39d02298639a4605e4433514bbf54c 100644
--- a/mhcflurry/downloads.yml
+++ b/mhcflurry/downloads.yml
@@ -30,7 +30,7 @@ releases:
               default: false
 
             - name: models_class1_pan_refined
-              url: https://github.com/openvax/mhcflurry/releases/download/1.4.0/models_class1_pan_refined.20191211c.tar.bz2
+              url: https://github.com/openvax/mhcflurry/releases/download/1.4.0/models_class1_pan_refined.20191212b.tar.bz2
               default: false
 
             - name: models_class1_pan_variants