diff --git a/modules/__init__.py b/modules/__init__.py
index f6e8d86..906e27c 100644
--- a/modules/__init__.py
+++ b/modules/__init__.py
@@ -11,7 +11,7 @@ def imwrite_unicode(path, img, params=None):
     root, ext = os.path.splitext(path)
     if not ext:
         ext = ".png"
-    result, encoded_img = cv2.imencode(f".{ext}", img, params if params is not None else [])
+    result, encoded_img = cv2.imencode(ext, img, params if params is not None else [])
     if result:
         encoded_img.tofile(path)
         return True