diff --git a/README.md b/README.md
index d37441ffee18ea9905e0a1f20bff0fd5617bed5a..5dcde0787e575e529c43ab2922c3225fccfdae7d 100644
--- a/README.md
+++ b/README.md
@@ -69,12 +69,12 @@ mqtt_host = "..."
 If desired, **sds011.lua** can be used to configure the SDS011 sensor.
 Currently, the following commands are supported
 
-* `sds011.set_report_mode(active)`
+* `port:write(sds011.set_report_mode(active))`
   * active == true: periodically report PM2.5 and PM10 values via UART
   * active == false: only report PM2.5 and PM10 values when queried
-* `sds011.sleep(sleep)`
+* `port:write(sds011.sleep(sleep))`
   * sleep == true: put sensor into sleep mode. The fan is turned off, no further measurements are performed
   * sleep == false: wake up sensor.
-* `sds011.set_work_period(period)`
+* `port:write(sds011.set_work_period(period))`
   * period == 0: continuous operation (about one measurement per second)
   * 0 < *period* ≤ 30: about one measurement every *period* minutes; fan turned off in-between