diff --git a/README.md b/README.md
index 825ec30..a2fe8b2 100644
--- a/README.md
+++ b/README.md
@@ -29,7 +29,9 @@ The instructions are for Raspbian under the assumption that the script will be i
 * Optional: Install the Adafruit tool that reads the sensor data<br>
 Skip this step if you already have it.<br>
 >
->    cd Zabbix-DHT/external/Adafruit_Python_DHT<br>
+>    cd Zabbix-DHT
+>    git submodule update --init
+>    cd external/Adafruit_Python_DHT<br>
 >    sudo python setup.py install
 
 * Edit the *readSensor* script and change as needed. At least the two variables **SENSOR** and **GPIOPIN** have to be adjusted to your setup.
@@ -62,4 +64,4 @@ Skip this step if you already have it.<br>
 After a few minutes you should see data starting to come in.
 
 ### Who?
-I'm codeing purely as a hobby and do it far too infrequent to have any kind of practice. So please bear with me if the code is amateurish...
\ No newline at end of file
+I'm codeing purely as a hobby and do it far too infrequent to have any kind of practice. So please bear with me if the code is amateurish...