diff --git a/build-number.txt b/build-number.txt
index 53c86ff..9524ef4 100644
--- a/build-number.txt
+++ b/build-number.txt
@@ -1 +1 @@
-417
+424
diff --git a/src/light_sensor.c b/src/light_sensor.c
index 4ec450f..8a87dbd 100644
--- a/src/light_sensor.c
+++ b/src/light_sensor.c
@@ -99,6 +99,17 @@ void LightSensor_Poll(void)
         {
             LightSensor_RelativeBrightness = LIGHTSENSOR_MAX;
         }
+
+        // Slowly reset limit values
+        static int decay_counter = 0;
+        decay_counter++;
+        if(decay_counter == LIGHTSENSOR_LIMIT_RESET_TIME * 1000
+            / LIGHTSENSOR_INTERVAL / LIGHTSENSOR_MAX)
+        {
+            decay_counter = 0;
+            LightSensor_MaximumBrightness -= 1;
+            LightSensor_MinimumBrightness += 1;
+        }
     }
 }
 
diff --git a/src/light_sensor.h b/src/light_sensor.h
index bc99ee2..1315b28 100644
--- a/src/light_sensor.h
+++ b/src/light_sensor.h
@@ -15,6 +15,10 @@
 // 'Forgetting factor' of the rolling brightness average
 #define LIGHTSENSOR_LAMBDA_BITS 4
 
+// Time until minimum and maximum value are completely reset (in seconds)
+#define LIGHTSENSOR_LIMIT_RESET_TIME \
+                                (24 * 60 * 60)
+
 // Bounds for converting absolute to relative brightness: Consider everything
 // near the minimum or maximum 0.0 or 1.0, respectively
 #define LIGHTSENSOR_LOW_BOUND   ((unsigned int)(0.005 * LIGHTSENSOR_MAX))