diff --git a/core/functions/tracks.py b/core/functions/tracks.py
index 72bfcce412c6c96cbe18fcaa7959461523a13737..730bc8d519a7cbe62976e2f687991dc17be7f623 100644
--- a/core/functions/tracks.py
+++ b/core/functions/tracks.py
@@ -168,7 +168,7 @@ def rec_bottom(d, k):
         return rec_bottom(d, d[k])
 
 
-def join_tracks(tracks, joinable_pairs, drop=False) -> pd.DataFrame:
+def join_tracks(tracks, joinable_pairs, drop=True) -> pd.DataFrame:
     """
     Join pairs of tracks from later tps towards the start.
 
@@ -186,7 +186,7 @@ def join_tracks(tracks, joinable_pairs, drop=False) -> pd.DataFrame:
 
     tmp = copy(tracks)
     for target, source in joinable_pairs:
-        tmp.loc[target] = join_track_pairs(tmp.loc[target], tmp.loc[source])
+        tmp.loc[target] = join_track_pair(tmp.loc[target], tmp.loc[source])
 
         if drop:
             tmp = tmp.drop(source)
@@ -194,9 +194,6 @@ def join_tracks(tracks, joinable_pairs, drop=False) -> pd.DataFrame:
     return tmp
 
 
-from copy import copy
-
-
 def join_track_pair(target, source):
     tgt_copy = copy(target)
     end = find_1st(target.values[::-1], 0, cmp_larger)