diff --git a/innofw/core/datasets/image_infer.py b/innofw/core/datasets/image_infer.py
index 26d3992f..61e4efd7 100644
--- a/innofw/core/datasets/image_infer.py
+++ b/innofw/core/datasets/image_infer.py
@@ -36,7 +36,7 @@ def __getitem__(self, index: int):
         if Path(self.image_dir).is_dir():
             image_name = self.image_names[index]
             image = cv2.imread(
-                Path(self.image_dir, image_name), cv2.IMREAD_COLOR
+                str(Path(self.image_dir, image_name)), cv2.IMREAD_COLOR
             )
         else:
             image = cv2.imread(self.image_dir, cv2.IMREAD_COLOR)