diff --git a/noxfile.py b/noxfile.py
index b62092e97..f47f2a055 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -101,7 +101,7 @@ def default(session, install_extras=True):
         CURRENT_DIRECTORY / "testing" / f"constraints-{session.python}.txt"
     )
     # Install all test dependencies, then install this package in-place.
-    session.install("mock", "pytest", "pytest-cov", "brotli", "-c", constraints_path)
+    session.install("mock", "pytest", "pytest-cov", "brotli", "grpcio", "grpcio-status", "-c", constraints_path)
 
     if install_extras:
         session.install("opentelemetry-api", "opentelemetry-sdk")
diff --git a/owlbot.py b/owlbot.py
index 055b4db9c..77acf42e6 100644
--- a/owlbot.py
+++ b/owlbot.py
@@ -42,6 +42,7 @@
             # Exclude autogenerated constraints files for Python 3.7/3.9
             "testing/constraints-3.7.txt",
             "testing/constraints-3.9.txt",
+            "tests/unit/__init__.py",
         ],
     )
 s.remove_staging_dirs()