diff --git a/rtk_rover_recorder.py b/rtk_rover_recorder.py
index e6606ba..b8120b7 100644
--- a/rtk_rover_recorder.py
+++ b/rtk_rover_recorder.py
@@ -516,13 +516,16 @@ class Recorder:
                 self.csv_fh.flush()
 
     def close(self):
-        with self.lock:
+        # Do not call self.stop() while holding self.lock:
+        # stop() also takes the same lock -> deadlock with threading.Lock.
+        try:
+            if self.session_id:
+                self.stop()
+        finally:
             try:
-                if self.session_id:
-                    self.stop()
-            finally:
-                try: self.conn.close()
-                except: pass
+                self.conn.close()
+            except Exception:
+                pass
 
 # -------------------- UI helpers --------------------
 def fix_type_str(pvt) -> str: