diff --git a/Dockerfile b/Dockerfile
index c75534132..0dcfac5b6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,8 @@ RUN make build-e2e --warn-undefined-variables
 
 FROM registry.access.redhat.com/ubi8/ubi-minimal:latest
 ENV USER_UID=10001
-
+# If proxy is added here to resolve build issue, remove it in the codes (E.g., call os.Unsetenv at main.go),
+# or the codes will use it and cause an error, the container cannot be started.
 COPY --from=builder /go/src/open-cluster-management.io/placement/placement /
 COPY --from=builder /go/src/open-cluster-management.io/placement/e2e.test /
 RUN microdnf update && microdnf clean all