diff --git a/oxtimelines/timeline.py b/oxtimelines/timeline.py
index 8be0054..e3a2710 100644
--- a/oxtimelines/timeline.py
+++ b/oxtimelines/timeline.py
@@ -586,8 +586,8 @@ class Timelines():
             # open small tile
             if small_tile_x == 0:
                 image_mode = 'L' if mode == 'audio' else 'RGB'
-                self.small_tile_i = int(index / 60)
-                if self.small_tile_i < self.small_tile_n - 1:
+                small_tile_i = int(index / 60)
+                if small_tile_i < self.small_tile_n - 1:
                     w = self.small_tile_w
                 else:
                     w = self.small_tile_last_w
@@ -603,8 +603,9 @@ class Timelines():
             self.small_tile_image[small_mode].paste(resized, paste)
             # save small tile
             if small_tile_x == self.small_tile_w - 60 or self.frame_i == self.frame_n - 1:
+                small_tile_i = int(index / 60)
                 tile_file = '%stimeline%s%dp%d.jpg' % (
-                    self.tile_path, small_mode, self.small_tile_h, self.small_tile_i
+                    self.tile_path, small_mode, self.small_tile_h, small_tile_i
                 )
                 self.small_tile_image[small_mode].save(tile_file)
                 if self.log: