diff --git a/monitor/fan.cpp b/monitor/fan.cpp
index a421290..2c29cb3 100644
--- a/monitor/fan.cpp
+++ b/monitor/fan.cpp
@@ -40,6 +40,7 @@
          System& system) :
     _bus(bus),
     _name(def.name), _deviation(def.deviation),
+    _upperDeviation(def.upperDeviation),
     _numSensorFailsForNonFunc(def.numSensorFailsForNonfunc),
     _trustManager(trust),
 #ifdef MONITOR_USE_JSON
@@ -359,7 +360,7 @@
     }
 
     auto actual = static_cast<uint64_t>(sensor.getInput());
-    auto range = sensor.getRange(_deviation);
+    auto range = sensor.getRange(_deviation, _upperDeviation);
 
     return ((actual < range.first) ||
             (range.second && actual > range.second.value()));
@@ -372,7 +373,7 @@
         return;
     }
 
-    auto range = sensor.getRange(_deviation);
+    auto range = sensor.getRange(_deviation, _upperDeviation);
     std::string rangeMax = "NoMax";
     if (range.second)
     {
diff --git a/monitor/fan.hpp b/monitor/fan.hpp
index 75c2213..5892ba2 100644
--- a/monitor/fan.hpp
+++ b/monitor/fan.hpp
@@ -258,6 +258,13 @@
     const size_t _deviation;
 
     /**
+     * @brief The percentage that the input speed must be above
+     *        the target speed to be considered an error.
+     *        Between 0 and 100.
+     */
+    const size_t _upperDeviation;
+
+    /**
      * The number of sensors that must be nonfunctional at the
      * same time in order for the fan to be set to nonfunctional
      * in the inventory.
diff --git a/monitor/gen-fan-monitor-defs.py b/monitor/gen-fan-monitor-defs.py
index bbd8368..dac5de7 100755
--- a/monitor/gen-fan-monitor-defs.py
+++ b/monitor/gen-fan-monitor-defs.py
@@ -55,6 +55,7 @@
                   ${fan_data.get('functional_delay', 0)},
                   ${fan_data.get('allowed_out_of_range_time', {})},
                   ${fan_data['deviation']},
+                  ${fan_data.get('upper_deviation', fan_data['deviation'])},
                   ${fan_data['num_sensors_nonfunc_for_fan_nonfunc']},
                   0, // Monitor start delay - not used in YAML configs
                   0, // Count interval - not used in YAML configs
diff --git a/monitor/json_parser.cpp b/monitor/json_parser.cpp
index d81d767..4d06540 100644
--- a/monitor/json_parser.cpp
+++ b/monitor/json_parser.cpp
@@ -221,6 +221,24 @@
             throw std::runtime_error(msg.c_str());
         }
 
+        // Upper deviation defaults to the deviation value and
+        // can also be separately specified.
+        size_t upperDeviation = deviation;
+        if (fan.contains("upper_deviation"))
+        {
+            upperDeviation = fan["upper_deviation"].get<size_t>();
+            if (100 < upperDeviation)
+            {
+                auto msg =
+                    fmt::format("Invalid upper_deviation of {} found, must "
+                                "be between 0 and 100",
+                                upperDeviation);
+
+                log<level::ERR>(msg.c_str());
+                throw std::runtime_error(msg.c_str());
+            }
+        }
+
         // Construct the sensor definitions for this fan
         auto sensorDefs = getSensorDefs(fan["sensors"]);
 
@@ -361,6 +379,7 @@
                           .funcDelay = funcDelay,
                           .timeout = timeout,
                           .deviation = deviation,
+                          .upperDeviation = upperDeviation,
                           .numSensorFailsForNonfunc = nonfuncSensorsCount,
                           .monitorStartDelay = monitorDelay,
                           .countInterval = countInterval,
diff --git a/monitor/tach_sensor.cpp b/monitor/tach_sensor.cpp
index 9e05009..3030d5c 100644
--- a/monitor/tach_sensor.cpp
+++ b/monitor/tach_sensor.cpp
@@ -207,11 +207,12 @@
 }
 
 std::pair<uint64_t, std::optional<uint64_t>>
-    TachSensor::getRange(const size_t deviation) const
+    TachSensor::getRange(const size_t lowerDeviation,
+                         const size_t upperDeviation) const
 {
     // Determine min/max range applying the deviation
-    uint64_t min = getTarget() * (100 - deviation) / 100;
-    std::optional<uint64_t> max = getTarget() * (100 + deviation) / 100;
+    uint64_t min = getTarget() * (100 - lowerDeviation) / 100;
+    std::optional<uint64_t> max = getTarget() * (100 + upperDeviation) / 100;
 
     // Adjust the min/max range by applying the factor & offset
     min = min * _factor + _offset;
diff --git a/monitor/tach_sensor.hpp b/monitor/tach_sensor.hpp
index 875c578..b4dc5b5 100644
--- a/monitor/tach_sensor.hpp
+++ b/monitor/tach_sensor.hpp
@@ -344,12 +344,16 @@
     /**
      * @brief Get the current allowed range of speeds
      *
-     * @param[in] deviation - The configured deviation(in percent) allowed
+     * @param[in] lowerDeviation - The configured lower deviation(in percent)
+     *                             allowed
+     * @param[in] upperDeviation - The configured upper deviation(in percent)
+     *                             allowed
      *
      * @return pair - Min/Max(optional) range of speeds allowed
      */
     std::pair<uint64_t, std::optional<uint64_t>>
-        getRange(const size_t deviation) const;
+        getRange(const size_t lowerDeviation,
+                 const size_t upperDeviation) const;
 
     /**
      * @brief Processes the current state of the sensor
diff --git a/monitor/types.hpp b/monitor/types.hpp
index 30b416f..fd53522 100644
--- a/monitor/types.hpp
+++ b/monitor/types.hpp
@@ -121,6 +121,7 @@
     size_t funcDelay;
     size_t timeout;
     size_t deviation;
+    size_t upperDeviation;
     size_t numSensorFailsForNonfunc;
     size_t monitorStartDelay;
     size_t countInterval;