diff --git a/firmware/sensor_wind.ino b/firmware/sensor_wind.ino
index 080329d..b01b86e 100644
--- a/firmware/sensor_wind.ino
+++ b/firmware/sensor_wind.ino
@@ -76,8 +76,9 @@ boolean check_measure_wind_done()
       previous_pin_state = tmp_pin_state;
       tmp_pin_state = digitalRead(ANEMOMETER_PIN);
 
-      if (previous_pin_state != tmp_pin_state && previous_pin_state != WIND_DEFAULT_MEAS_INIT)
+      if (previous_pin_state != tmp_pin_state && tmp_pin_state == 0 && previous_pin_state != WIND_DEFAULT_MEAS_INIT)
       {
+        // only count rotations on falling edges
         anemometerRotations++;
 #ifdef DEBUG
         Serial.print("*");