diff --git a/builder/test/tests.sh b/builder/test/tests.sh
index 3ee0302d..8133bf0f 100755
--- a/builder/test/tests.sh
+++ b/builder/test/tests.sh
@@ -27,7 +27,11 @@ tcpdump --version
 monkey --version
 pigpiod -v
 i2cdetect -V
+# butterfly uses its own venv, so we honor that
+. /root/butterfly_env/bin/activate
 butterfly -h
+# deactivate venv as needed
+deactivate
 espeak --version
 mjpg_streamer --version