diff --git a/ci/buildkite.yml b/ci/buildkite.yml
index e0c18e6e0f..7af1bb6a5b 100644
--- a/ci/buildkite.yml
+++ b/ci/buildkite.yml
@@ -4,7 +4,7 @@ steps:
     env:
       CARGO_TARGET_CACHE_NAME: "stable"
     timeout_in_minutes: 30
-  - command: "ci/docker-run.sh solanalabs/rust-nightly ci/test-bench.sh"
+  - command: "ci/docker-run.sh solanalabs/rust-nightly:2018-09-28 ci/test-bench.sh"
     name: "bench [public]"
     env:
       CARGO_TARGET_CACHE_NAME: "nightly"