diff --git a/README.md b/README.md
index 7fdec0515ae22508d53465e4e37bf904569dc848..7999cbfe8bea2f3f4698d61952c9b89ddc9d9ad7 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ This Python3 code uses other Python3 modules:
 
 - opcua
 - recordclass
+- yaml
 - numpy
 
 We recommend to install a virtual environment and then install the dependencies there.  For convenience we have added the relevant modules to the file `requirements.txt` that can be used to install them with pip3: `python3 -m pip install -r requirements.txt`