diff --git a/news.d/bugfix/1636.core.md b/news.d/bugfix/1636.core.md
new file mode 100644
index 000000000..3ccacdeed
--- /dev/null
+++ b/news.d/bugfix/1636.core.md
@@ -0,0 +1 @@
+Closes serial ports upon disconnection to ensure clean reconnections.
diff --git a/plover/machine/base.py b/plover/machine/base.py
index 4841c5e36..7f287d35c 100644
--- a/plover/machine/base.py
+++ b/plover/machine/base.py
@@ -212,6 +212,7 @@ def __init__(self, serial_params):
 
         """
         ThreadedStenotypeBase.__init__(self)
+        self._on_unhandled_exception(self._handle_disconnect)
         self.serial_port = None
         self.serial_params = serial_params
 
@@ -221,6 +222,10 @@ def _close_port(self):
         self.serial_port.close()
         self.serial_port = None
 
+    def _handle_disconnect(self):
+        self._close_port()
+        self._error()
+
     def start_capture(self):
         self._close_port()