diff --git a/.cargo/config.toml b/.cargo/config.toml
index bff29e6e..4c1262bc 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -1,2 +1,3 @@
 [build]
-rustflags = ["--cfg", "tokio_unstable"]
+# potentially faster. https://nnethercote.github.io/perf-book/build-configuration.html
+rustflags = ["-C", "target-cpu=native", "--cfg", "tokio_unstable"]
diff --git a/Dockerfile b/Dockerfile
index 29ed4f00..860ad7ea 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,8 +1,5 @@
 FROM rust:1-bullseye as builder
 
-# potentially faster. https://nnethercote.github.io/perf-book/build-configuration.html
-ENV RUSTFLAGS "-C target-cpu=native"
-
 WORKDIR /usr/src/web3-proxy
 COPY . .
 RUN --mount=type=cache,target=/usr/local/cargo/registry \