diff --git a/contrib/requirements/requirements-hw.txt b/contrib/requirements/requirements-hw.txt
index 582a31e14..3ec9a156b 100644
--- a/contrib/requirements/requirements-hw.txt
+++ b/contrib/requirements/requirements-hw.txt
@@ -11,3 +11,7 @@ ckcc-protocol>=0.7.7
 bitbox02>=6.0.0
 cbor>=1.0.0,<2.0.0
 pyserial>=3.5.0,<4.0.0
+
+# prefer older protobuf (see #7922)
+# (pulled in via e.g. keepkey and bitbox02)
+protobuf>=3.12,<4