diff --git a/.generator/Dockerfile b/.generator/Dockerfile
index afceb7fd4693..076f1aa86443 100644
--- a/.generator/Dockerfile
+++ b/.generator/Dockerfile
@@ -32,6 +32,10 @@ RUN apt-get update && \
     libffi-dev \
     libsqlite3-dev \
     libreadline-dev \
+    # Needed for `google-cloud-bigquery-storage` to avoid
+    # the error `ModuleNotFoundError: No module named '_lzma'`
+    # described in https://github.com/googleapis/google-cloud-python/issues/14884
+    liblzma-dev \
     # ------------------------------------------------------
     && apt-get clean && \
     rm -rf /var/lib/apt/lists/*
diff --git a/.generator/cli.py b/.generator/cli.py
index 3b520a8bfa24..791e6578e087 100644
--- a/.generator/cli.py
+++ b/.generator/cli.py
@@ -1041,9 +1041,9 @@ def _verify_library_namespace(library_id: str, repo: str, is_mono_repo: bool):
     for proto_file in library_path.rglob(proto_file):
         proto_path = str(proto_file.parent.relative_to(library_path))
         # Exclude proto paths which are not intended to be used for code generation.
-        # Generally any protos under the `samples` directory or in a
+        # Generally any protos under the `samples` or `tests` directories or in a
         # directory called `proto` are not used for code generation.
-        if proto_path.startswith("samples") or proto_path.endswith("proto"):
+        if proto_path.startswith("tests") or proto_path.startswith("samples") or proto_path.endswith("proto"):
             continue
         relevant_dirs.add(proto_file.parent)