diff --git a/core/tools/build_protobuf b/core/tools/build_protobuf
index 921fc95a1..0df512e43 100755
--- a/core/tools/build_protobuf
+++ b/core/tools/build_protobuf
@@ -1,5 +1,6 @@
 #!/bin/bash
 set -e
+cd $(dirname $0)
 
 rm -f ../src/trezor/messages/[A-Z]*.py
 ../vendor/trezor-common/protob/pb2py \