diff --git a/downloads-generation/models_class1_pan_refined/hyperparameters.yaml b/downloads-generation/models_class1_pan_refined/hyperparameters.yaml
index 9dbb95757b5930a1fb7e346901efb1801cdaf83e..a1747f7ada068f5f37c10560b020e168e706222b 100644
--- a/downloads-generation/models_class1_pan_refined/hyperparameters.yaml
+++ b/downloads-generation/models_class1_pan_refined/hyperparameters.yaml
@@ -2,7 +2,7 @@
 # Batch generation
 #########################
 batch_generator_validation_split: 0.1
-batch_generator_batch_size: 10240
+batch_generator_batch_size: 1024
 batch_generator_affinity_fraction: 0.5
 max_epochs: 500
 random_negative_rate: 1.0
diff --git a/mhcflurry/class1_presentation_neural_network.py b/mhcflurry/class1_presentation_neural_network.py
index 58be681341adab8f42461b7920e535433e02a8f0..2e1156e619deaa4762a0a1146b12a157f5f50422 100644
--- a/mhcflurry/class1_presentation_neural_network.py
+++ b/mhcflurry/class1_presentation_neural_network.py
@@ -453,7 +453,7 @@ class Class1PresentationNeuralNetwork(object):
 
         allele_representations_hash = self.set_allele_representations(
             allele_representations)
-        loss_reduction = "none"
+        loss_reduction = "sum_over_batch_size"
         self.network.compile(
             loss=[
                 affinities_loss.get_keras_loss(reduction=loss_reduction),
diff --git a/mhcflurry/downloads.yml b/mhcflurry/downloads.yml
index 5de672d9b7e7d7fff85aac79fbca36ebd57c15ea..286121fd3e8a21953cf9fb495bd6a008d1807283 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.20191211.tar.bz2
+              url: https://github.com/openvax/mhcflurry/releases/download/1.4.0/models_class1_pan_refined.20191211b.tar.bz2
               default: false
 
             - name: models_class1_pan_variants