diff --git a/clip/model.py b/clip/model.py
index 808bf16..232b779 100644
--- a/clip/model.py
+++ b/clip/model.py
@@ -419,7 +419,7 @@ def build_model(state_dict: dict):
     vocab_size = state_dict["token_embedding.weight"].shape[0]
     transformer_width = state_dict["ln_final.weight"].shape[0]
     transformer_heads = transformer_width // 64
-    transformer_layers = len(set(k.split(".")[2] for k in state_dict if k.startswith(f"transformer.resblocks")))
+    transformer_layers = len(set(k.split(".")[2] for k in state_dict if k.startswith("transformer.resblocks")))
 
     model = CLIP(
         embed_dim,