diff --git a/.flake8 b/.flake8
index 39288e9b1..8555d626c 100644
--- a/.flake8
+++ b/.flake8
@@ -20,4 +20,5 @@ exclude =
   ext/opentelemetry-ext-jaeger/build/*
   docs/examples/opentelemetry-example-app/src/opentelemetry_example_app/grpc/gen/
   docs/examples/opentelemetry-example-app/build/*
+  opentelemetry-proto/build/*
   opentelemetry-proto/src/opentelemetry/proto/