diff --git a/meshtastic/tests/test_mesh_interface.py b/meshtastic/tests/test_mesh_interface.py
index b96f9e4..c0a0135 100644
--- a/meshtastic/tests/test_mesh_interface.py
+++ b/meshtastic/tests/test_mesh_interface.py
@@ -10,6 +10,7 @@ from ..mesh_interface import MeshInterface
 from ..node import Node
 from .. import mesh_pb2
 from ..__init__ import LOCAL_ADDR, BROADCAST_ADDR
+from ..radioconfig_pb2 import RadioConfig
 
 
 @pytest.mark.unit
@@ -164,6 +165,22 @@ def test_sendPosition(reset_globals, caplog):
     assert re.search(r'p.time:', caplog.text, re.MULTILINE)
 
 
+@pytest.mark.unit
+def test_close_with_heartbeatTimer(reset_globals, caplog):
+    """Test close() with heartbeatTimer"""
+    iface = MeshInterface(noProto=True)
+    anode = Node('foo', 'bar')
+    radioConfig = RadioConfig()
+    radioConfig.preferences.phone_timeout_secs = 10
+    anode.radioConfig = radioConfig
+    iface.localNode = anode
+    assert iface.heartbeatTimer is None
+    with caplog.at_level(logging.DEBUG):
+        iface._startHeartbeat()
+        assert iface.heartbeatTimer is not None
+        iface.close()
+
+
 @pytest.mark.unit
 def test_handleFromRadio_empty_payload(reset_globals, caplog):
     """Test _handleFromRadio"""