diff --git a/Adafruit_BME280.cpp b/Adafruit_BME280.cpp
index 725ec1a..38f8698 100644
--- a/Adafruit_BME280.cpp
+++ b/Adafruit_BME280.cpp
@@ -256,6 +256,8 @@ float Adafruit_BME280::readTemperature(void)
 float Adafruit_BME280::readPressure(void) {
   int64_t var1, var2, p;
 
+  readTemperature(); // must be done first to get t_fine
+
   int32_t adc_P = read16(BME280_REGISTER_PRESSUREDATA);
   adc_P <<= 8;
   adc_P |= read8(BME280_REGISTER_PRESSUREDATA+2);
@@ -289,6 +291,8 @@ float Adafruit_BME280::readPressure(void) {
 /**************************************************************************/
 float Adafruit_BME280::readHumidity(void) {
 
+  readTemperature(); // must be done first to get t_fine
+
   int32_t adc_H = read16(BME280_REGISTER_HUMIDDATA);
 
   int32_t v_x1_u32r;