diff --git a/.github/actions/package/Dockerfile b/.github/actions/package/Dockerfile
index a504e9202..2feccebf2 100644
--- a/.github/actions/package/Dockerfile
+++ b/.github/actions/package/Dockerfile
@@ -1,4 +1,4 @@
-ARG BASE_IMAGE=rust:1.41.0-buster
+ARG BASE_IMAGE=rust:1.42.0-buster
 FROM $BASE_IMAGE
 WORKDIR /linkerd
 RUN apt-get update && \
diff --git a/.github/actions/remote/Dockerfile b/.github/actions/remote/Dockerfile
index d3cc5d775..28cdc9982 100644
--- a/.github/actions/remote/Dockerfile
+++ b/.github/actions/remote/Dockerfile
@@ -1,5 +1,5 @@
 # Intended to be run on a remote DOCKER_HOST
-ARG RUST_IMAGE=rust:1.37.0-buster
+ARG RUST_IMAGE=rust:1.42.0-buster
 FROM $RUST_IMAGE as build
 WORKDIR /usr/src/linkerd2-proxy
 COPY . ./
diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 4e05d5faf..0bd9aded7 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -10,7 +10,7 @@ jobs:
   fmt:
     runs-on: ubuntu-18.04
     container:
-      image: docker://rust:1.41.0-buster
+      image: docker://rust:1.42.0-buster
     steps:
     - uses: actions/checkout@v1
     - run: rustup component add rustfmt
@@ -19,7 +19,7 @@ jobs:
   lib:
     runs-on: ubuntu-18.04
     container:
-      image: docker://rust:1.41.0-buster
+      image: docker://rust:1.42.0-buster
     steps:
     - uses: actions/checkout@v1
     - run: make test-lib
diff --git a/Dockerfile b/Dockerfile
index d6486adff..41b5becc1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -17,7 +17,7 @@
 #     :; docker buildx build . --load
 
 # Please make changes via update-rust-version.sh
-ARG RUST_IMAGE=rust:1.41.0-buster
+ARG RUST_IMAGE=rust:1.42.0-buster
 
 # Use an arbitrary ~recent edge release image to get the proxy
 # identity-initializing wrapper.
@@ -38,7 +38,7 @@ ARG PROXY_FEATURES
 WORKDIR /usr/src/linkerd2-proxy
 COPY . .
 RUN --mount=type=cache,target=target \
-    --mount=type=cache,from=rust:1.41.0-buster,source=/usr/local/cargo,target=/usr/local/cargo \
+    --mount=type=cache,from=rust:1.42.0-buster,source=/usr/local/cargo,target=/usr/local/cargo \
     mkdir -p /out && \
     if [ -n "$PROXY_UNOPTIMIZED" ]; then \
       (cd linkerd2-proxy && cargo build --locked --features="$PROXY_FEATURES") && \
diff --git a/profiling/Dockerfile-proxy b/profiling/Dockerfile-proxy
index fbfb90620..1cb2ecbba 100644
--- a/profiling/Dockerfile-proxy
+++ b/profiling/Dockerfile-proxy
@@ -1,4 +1,4 @@
-ARG RUST_IMAGE=rust:1.41.0-buster
+ARG RUST_IMAGE=rust:1.42.0-buster
 ARG RUNTIME_IMAGE=debian:bullseye-slim
 ARG RUSTFLAGS="-C debuginfo=2 -C lto=off"
 ## Builds the proxy as incrementally as possible.
diff --git a/rust-toolchain b/rust-toolchain
index 7d47e5998..a50908ca3 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-1.41.0
+1.42.0
diff --git a/update-rust-version.sh b/update-rust-version.sh
index 91095f69d..b0f85a792 100755
--- a/update-rust-version.sh
+++ b/update-rust-version.sh
@@ -14,7 +14,7 @@ if ! echo "$VERSION" | grep -qE '^[0-9]+\.[0-9]+\.[0-9]+$' ; then
 fi
 
 echo "$VERSION" > rust-toolchain
-sed -i'' -Ee "s/rust:[0-9]+\.[0-9]+\.[0-9]+/rust:$VERSION/" Dockerfile
-
-find .github -name \*.yml -or -name Dockerfile\* \
+find . -name Dockerfile\* \
+    -exec sed -i'' -Ee "s|rust:[0-9]+\.[0-9]+\.[0-9]+|rust:$VERSION|" '{}' \;
+find .github -name \*.yml \
     -exec sed -i'' -Ee "s|rust:[0-9]+\.[0-9]+\.[0-9]+|rust:$VERSION|" '{}' \;