diff --git a/pid/pidloop.cpp b/pid/pidloop.cpp
index 711ba2f..a5d0daf 100644
--- a/pid/pidloop.cpp
+++ b/pid/pidloop.cpp
@@ -48,8 +48,11 @@
 
 void pidControlLoop(std::shared_ptr<ZoneInterface> zone,
                     std::shared_ptr<boost::asio::steady_timer> timer,
-                    bool first, int ms100cnt)
+                    const bool* isCanceling, bool first, int ms100cnt)
 {
+    if (*isCanceling)
+        return;
+
     if (first)
     {
         if (loggingEnabled)
@@ -62,71 +65,71 @@
     }
 
     timer->expires_after(std::chrono::milliseconds(100));
-    timer->async_wait(
-        [zone, timer, ms100cnt](const boost::system::error_code& ec) mutable {
-            if (ec == boost::asio::error::operation_aborted)
-            {
-                return; // timer being canceled, stop loop
-            }
+    timer->async_wait([zone, timer, ms100cnt, isCanceling](
+                          const boost::system::error_code& ec) mutable {
+        if (ec == boost::asio::error::operation_aborted)
+        {
+            return; // timer being canceled, stop loop
+        }
 
-            /*
-             * This should sleep on the conditional wait for the listen thread
-             * to tell us it's in sync.  But then we also need a timeout option
-             * in case phosphor-hwmon is down, we can go into some weird failure
-             * more.
-             *
-             * Another approach would be to start all sensors in worst-case
-             * values, and fail-safe mode and then clear out of fail-safe mode
-             * once we start getting values.  Which I think it is a solid
-             * approach.
-             *
-             * For now this runs before it necessarily has any sensor values.
-             * For the host sensors they start out in fail-safe mode.  For the
-             * fans, they start out as 0 as input and then are adjusted once
-             * they have values.
-             *
-             * If a fan has failed, it's value will be whatever we're told or
-             * however we retrieve it.  This program disregards fan values of 0,
-             * so any code providing a fan speed can set to 0 on failure and
-             * that fan value will be effectively ignored.  The PID algorithm
-             * will be unhappy but nothing bad will happen.
-             *
-             * TODO(venture): If the fan value is 0 should that loop just be
-             * skipped? Right now, a 0 value is ignored in
-             * FanController::inputProc()
-             */
+        /*
+         * This should sleep on the conditional wait for the listen thread
+         * to tell us it's in sync.  But then we also need a timeout option
+         * in case phosphor-hwmon is down, we can go into some weird failure
+         * more.
+         *
+         * Another approach would be to start all sensors in worst-case
+         * values, and fail-safe mode and then clear out of fail-safe mode
+         * once we start getting values.  Which I think it is a solid
+         * approach.
+         *
+         * For now this runs before it necessarily has any sensor values.
+         * For the host sensors they start out in fail-safe mode.  For the
+         * fans, they start out as 0 as input and then are adjusted once
+         * they have values.
+         *
+         * If a fan has failed, it's value will be whatever we're told or
+         * however we retrieve it.  This program disregards fan values of 0,
+         * so any code providing a fan speed can set to 0 on failure and
+         * that fan value will be effectively ignored.  The PID algorithm
+         * will be unhappy but nothing bad will happen.
+         *
+         * TODO(venture): If the fan value is 0 should that loop just be
+         * skipped? Right now, a 0 value is ignored in
+         * FanController::inputProc()
+         */
 
-            // Check if we should just go back to sleep.
-            if (zone->getManualMode())
-            {
-                pidControlLoop(zone, timer, false, ms100cnt);
-                return;
-            }
+        // Check if we should just go back to sleep.
+        if (zone->getManualMode())
+        {
+            pidControlLoop(zone, timer, isCanceling, false, ms100cnt);
+            return;
+        }
 
-            // Get the latest fan speeds.
-            zone->updateFanTelemetry();
+        // Get the latest fan speeds.
+        zone->updateFanTelemetry();
 
-            if (10 <= ms100cnt)
-            {
-                ms100cnt = 0;
+        if (10 <= ms100cnt)
+        {
+            ms100cnt = 0;
 
-                processThermals(zone);
-            }
+            processThermals(zone);
+        }
 
-            // Run the fan PIDs every iteration.
-            zone->processFans();
+        // Run the fan PIDs every iteration.
+        zone->processFans();
 
-            if (loggingEnabled)
-            {
-                std::ostringstream out;
-                out << "," << zone->getFailSafeMode() << std::endl;
-                zone->writeLog(out.str());
-            }
+        if (loggingEnabled)
+        {
+            std::ostringstream out;
+            out << "," << zone->getFailSafeMode() << std::endl;
+            zone->writeLog(out.str());
+        }
 
-            ms100cnt += 1;
+        ms100cnt += 1;
 
-            pidControlLoop(zone, timer, false, ms100cnt);
-        });
+        pidControlLoop(zone, timer, isCanceling, false, ms100cnt);
+    });
 }
 
 } // namespace pid_control