diff --git a/Adafruit_BMP085_U.h b/Adafruit_BMP085_U.h
index 67bd007..adbf8ea 100644
--- a/Adafruit_BMP085_U.h
+++ b/Adafruit_BMP085_U.h
@@ -99,6 +99,7 @@ class Adafruit_BMP085_Unified : public Adafruit_Sensor
     void  getTemperature(float *temp);
     void  getPressure(float *pressure);
     float pressureToAltitude(float seaLevel, float atmospheric, float temp);
+    float seaLevelForAltitude(float altitude, float atmospheric, float temp);
     void  getEvent(sensors_event_t*);
     void  getSensor(sensor_t*);