diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
index 03bfcc40bb7c..e91e2103a6c7 100644
--- a/drivers/hwmon/cros_ec_hwmon.c
+++ b/drivers/hwmon/cros_ec_hwmon.c
@@ -146,9 +146,17 @@ static bool cros_ec_hwmon_is_error_temp(u8 temp)
 	       temp == EC_TEMP_SENSOR_NOT_CALIBRATED;
 }
 
+/* This differs slightly from the variant in units.h to avoid rounding inconsistencies. */
+#define CROS_EC_HWMON_ABSOLUTE_ZERO_MILLICELSIUS (-273000)
+
+static long cros_ec_hwmon_kelvin_to_millicelsius(long t)
+{
+	return t * MILLIDEGREE_PER_DEGREE + CROS_EC_HWMON_ABSOLUTE_ZERO_MILLICELSIUS;
+}
+
 static long cros_ec_hwmon_temp_to_millicelsius(u8 temp)
 {
-	return kelvin_to_millicelsius((((long)temp) + EC_TEMP_SENSOR_OFFSET));
+	return cros_ec_hwmon_kelvin_to_millicelsius((((long)temp) + EC_TEMP_SENSOR_OFFSET));
 }
 
 static bool cros_ec_hwmon_attr_is_temp_threshold(u32 attr)
@@ -227,7 +235,7 @@ static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 								cros_ec_hwmon_attr_to_thres(attr),
 								&threshold);
 			if (ret == 0)
-				*val = kelvin_to_millicelsius(threshold);
+				*val = cros_ec_hwmon_kelvin_to_millicelsius(threshold);
 		}
 	}