diff --git a/src/patchwork/app.py b/src/patchwork/app.py
index f0f10cc..007a898 100644
--- a/src/patchwork/app.py
+++ b/src/patchwork/app.py
@@ -362,7 +362,7 @@ def clear_markers():
     if not markers:
         return False
     
-    [x.delete() for x in markers]
+    [x.delete() for x in markers if x.customdata == "patchwork_marker"]
     force_refresh = True
     markers = copy.copy(resolve.active_timeline.markers)
     return True