diff --git a/mhcflurry/class1_allele_specific/cross_validation.py b/mhcflurry/class1_allele_specific/cross_validation.py
index 4d3dc41a4f7312e132c39ff30364ea1058621ff6..184bae580ea4ed0c87efd9f0f9b9720a7a66dee1 100644
--- a/mhcflurry/class1_allele_specific/cross_validation.py
+++ b/mhcflurry/class1_allele_specific/cross_validation.py
@@ -192,4 +192,4 @@ def cross_validation_folds(
             for (result_fold, imputation_result) in zip(
                 result_folds, imputation_results)
         ]
-    return result_fold
+    return result_folds
diff --git a/mhcflurry/parallelism.py b/mhcflurry/parallelism.py
index c82b40e0bce3d51bf795fe019afa1d633004a247..faecc871469210058ebb11f3323ae0a1ccdc20ce 100644
--- a/mhcflurry/parallelism.py
+++ b/mhcflurry/parallelism.py
@@ -14,6 +14,7 @@ class ParallelBackend(object):
         self.module = module
         self.verbose = verbose
 
+
 class KubefaceParallelBackend(ParallelBackend):
     """
     ParallelBackend that uses kubeface
diff --git a/test/test_class1_allele_specific_cv_and_train_command.py b/test/test_class1_allele_specific_cv_and_train_command.py
index f6e52d87a4aa73ba6555f4d0c86c493b58a48a85..9f0c193bb2330ecfb0aa6438fd67cd67d61d43a6 100644
--- a/test/test_class1_allele_specific_cv_and_train_command.py
+++ b/test/test_class1_allele_specific_cv_and_train_command.py
@@ -61,6 +61,7 @@ def test_small_run():
         "--alleles", "HLA-A0201", "HLA-A0301",
         "--verbose",
         "--num-local-threads", "1",
+        "--storage-prefix", "/tmp/",
     ]
     print("Running cv_and_train_command with args: %s " % str(args))
 
diff --git a/test/test_cross_validation.py b/test/test_cross_validation.py
index cf95333b81c993ef0282af397abd85658f737d8b..c0d4296e815dad534d8cb8f46b799dd0343f9f69 100644
--- a/test/test_cross_validation.py
+++ b/test/test_cross_validation.py
@@ -77,7 +77,7 @@ def test_cross_validation_with_imputation():
         n_imputations=2, n_burn_in=1, n_nearest_columns=25)
     train_data = (
         mhcflurry.dataset.Dataset.from_csv(
-            get_path("data_kim2014" , "bdata.2009.mhci.public.1.txt"))
+            get_path("data_kim2014", "bdata.2009.mhci.public.1.txt"))
         .get_alleles(["HLA-A0201", "HLA-A0202", "HLA-A0301"]))
 
     folds = cross_validation_folds(