diff --git a/server/requirements-hw.txt b/server/requirements-hw.txt
new file mode 100644
index 0000000..06d6d38
--- /dev/null
+++ b/server/requirements-hw.txt
@@ -0,0 +1,3 @@
+-r requirements.txt
+pyserial
+spidev
diff --git a/server/requirements.txt b/server/requirements.txt
index 09dc06f..cf076c8 100644
--- a/server/requirements.txt
+++ b/server/requirements.txt
@@ -1,7 +1,5 @@
 numpy
 websockets==10.4
 dpath
-pyserial
-spidev
 # web/ (the browser client) needs none of these - it's static HTML/JS
 # served straight from the stdlib's http.server, no new dependency.