diff --git a/include/rtlsdr_i2c.h b/include/rtlsdr_i2c.h
index 6faf141..b683896 100644
--- a/include/rtlsdr_i2c.h
+++ b/include/rtlsdr_i2c.h
@@ -2,6 +2,7 @@
 #define __I2C_H
 
 int rtlsdr_check_dongle_model(void *dev, char *manufact_check, char *product_check);
+int rtlsdr_set_bias_tee_gpio(void *dev, int gpio, int on);
 uint32_t rtlsdr_get_tuner_clock(void *dev);
 int rtlsdr_i2c_write_fn(void *dev, uint8_t addr, uint8_t *buf, int len);
 int rtlsdr_i2c_read_fn(void *dev, uint8_t addr, uint8_t *buf, int len);