diff --git a/c_mpos/breakout/build.sh b/c_mpos/breakout/build.sh
index ded7ec92..3086e9b3 100755
--- a/c_mpos/breakout/build.sh
+++ b/c_mpos/breakout/build.sh
@@ -1,5 +1,7 @@
 . ~/.espressif/python_env/idf5.4_py3.11_env/bin/activate
 
+pip install pyelftools
+
 mydir=$(readlink -f "$0")
 mydir=$(dirname "$mydir")