diff --git a/src/eva/vision/data/datasets/_validators.py b/src/eva/vision/data/datasets/_validators.py
index 0a727411..212ca0dd 100644
--- a/src/eva/vision/data/datasets/_validators.py
+++ b/src/eva/vision/data/datasets/_validators.py
@@ -48,7 +48,7 @@ def check_dataset_integrity(
 
 def check_dataset_exists(dataset_dir: str, download_available: bool) -> None:
     if not os.path.isdir(dataset_dir):
-        error_message = "Dataset not found at '{dataset_dir}'."
+        error_message = f"Dataset not found at '{dataset_dir}'."
         if download_available:
             error_message += " You can set `download=True` to download the dataset automatically."
         raise FileNotFoundError(error_message)