diff --git a/tests/test_generation.py b/tests/test_generation.py
index 4df53638e..98c45a301 100644
--- a/tests/test_generation.py
+++ b/tests/test_generation.py
@@ -13,7 +13,7 @@
     torch._C._jit_set_profiling_executor(True)
     torch._C._jit_set_profiling_mode(False)
 
-models_to_test = open_clip.list_generative_models().difference(
+models_to_test = set(open_clip.list_generative_models()).difference(
     {"coca_roberta-ViT-B-32", "coca_base"}
 )