diff --git a/monkey/infection_monkey/telemetry/messengers/batching_telemetry_messenger.py b/monkey/infection_monkey/telemetry/messengers/batching_telemetry_messenger.py
index 4d34012d8..9dc051666 100644
--- a/monkey/infection_monkey/telemetry/messengers/batching_telemetry_messenger.py
+++ b/monkey/infection_monkey/telemetry/messengers/batching_telemetry_messenger.py
@@ -1,11 +1,11 @@
 import queue
 import threading
-import time
 from typing import Dict
 
 from infection_monkey.telemetry.i_batchable_telem import IBatchableTelem
 from infection_monkey.telemetry.i_telem import ITelem
 from infection_monkey.telemetry.messengers.i_telemetry_messenger import ITelemetryMessenger
+from infection_monkey.utils.timer import Timer
 
 DEFAULT_PERIOD = 5
 WAKES_PER_PERIOD = 4
@@ -40,8 +40,6 @@ class BatchingTelemetryMessenger(ITelemetryMessenger):
             self._period = period
 
             self._should_run_batch_thread = True
-            # TODO: Replace with infection_monkey.utils.timer.Timer
-            self._last_sent_time = time.time()
             self._telemetry_batches: Dict[str, IBatchableTelem] = {}
 
             self._manage_telemetry_batches_thread = None
@@ -59,21 +57,20 @@ class BatchingTelemetryMessenger(ITelemetryMessenger):
             self._manage_telemetry_batches_thread = None
 
         def _manage_telemetry_batches(self):
-            self._reset()
+            timer = Timer()
+            timer.set(self._period)
+            self._telemetry_batches = {}
 
             while self._should_run_batch_thread:
                 self._process_next_telemetry()
 
-                if self._period_elapsed():
+                if timer.is_expired():
                     self._send_telemetry_batches()
-                    self._reset()
+                    timer.reset()
+                    self._telemetry_batches = {}
 
             self._send_remaining_telemetry_batches()
 
-        def _reset(self):
-            self._last_sent_time = time.time()
-            self._telemetry_batches = {}
-
         def _process_next_telemetry(self):
             try:
                 telemetry = self._queue.get(block=True, timeout=self._period / WAKES_PER_PERIOD)
@@ -93,9 +90,6 @@ class BatchingTelemetryMessenger(ITelemetryMessenger):
             else:
                 self._telemetry_batches[telem_category] = new_telemetry
 
-        def _period_elapsed(self):
-            return (time.time() - self._last_sent_time) > self._period
-
         def _send_remaining_telemetry_batches(self):
             while not self._queue.empty():
                 self._process_next_telemetry()
diff --git a/monkey/infection_monkey/tunnel.py b/monkey/infection_monkey/tunnel.py
index b0f778534..26368bff6 100644
--- a/monkey/infection_monkey/tunnel.py
+++ b/monkey/infection_monkey/tunnel.py
@@ -8,6 +8,7 @@ from infection_monkey.network.firewall import app as firewall
 from infection_monkey.network.info import get_free_tcp_port, local_ips
 from infection_monkey.network.tools import check_tcp_port, get_interface_to_target
 from infection_monkey.transport.base import get_last_serve_time
+from infection_monkey.utils.timer import Timer
 
 logger = logging.getLogger(__name__)
 
@@ -181,8 +182,9 @@ class MonkeyTunnel(Thread):
 
         # wait till all of the tunnel clients has been disconnected, or no one used the tunnel in
         # QUIT_TIMEOUT seconds
-        # TODO: Replace with infection_monkey.utils.timer.Timer
-        while self._clients and (time.time() - get_last_serve_time() < QUIT_TIMEOUT):
+        timer = Timer()
+        timer.set(self._calculate_timeout())
+        while self._clients and not timer.is_expired():
             try:
                 search, address = self._broad_sock.recvfrom(BUFFER_READ)
                 if b"-" == search:
@@ -191,11 +193,19 @@ class MonkeyTunnel(Thread):
             except socket.timeout:
                 continue
 
+            timer.set(self._calculate_timeout())
+
         logger.info("Closing tunnel")
         self._broad_sock.close()
         proxy.stop()
         proxy.join()
 
+    def _calculate_timeout(self) -> float:
+        try:
+            return QUIT_TIMEOUT - (time.time() - get_last_serve_time())
+        except TypeError:  # get_last_serve_time() may return None
+            return 0.0
+
     def get_tunnel_for_ip(self, ip: str):
 
         if not self.local_port:
diff --git a/monkey/infection_monkey/utils/timer.py b/monkey/infection_monkey/utils/timer.py
index 2ed17d551..6095d466e 100644
--- a/monkey/infection_monkey/utils/timer.py
+++ b/monkey/infection_monkey/utils/timer.py
@@ -13,7 +13,8 @@ class Timer:
     def set(self, timeout_sec: float):
         """
         Set a timer
-        :param float timeout_sec: A fractional number of seconds to set the timeout for.
+        :param float timeout_sec: A nonnegative floating point number expressing the number of
+                                  seconds to set the timeout for.
         """
         self._timeout_sec = timeout_sec
         self._start_time = time.time()