diff --git a/dev/source/docs/building-setup-windows-cygwin.rst b/dev/source/docs/building-setup-windows-cygwin.rst
index 6fbbe60207..679567bfab 100644
--- a/dev/source/docs/building-setup-windows-cygwin.rst
+++ b/dev/source/docs/building-setup-windows-cygwin.rst
@@ -129,7 +129,8 @@ Set up directories/paths and extra packages in Cygwin
 
     ln -s /usr/bin/python3.7 /usr/bin/python
     ln -s /usr/bin/pip3.7 /usr/bin/pip
-    pip install empy pyserial pymavlink
+    pip install pyserial pymavlink
+    pip install empy==3.3.4
 
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 =========================