diff --git a/.azure/azure-pipelines.yml b/.azure/azure-pipelines.yml
index caa63e0164..ec77a1de97 100644
--- a/.azure/azure-pipelines.yml
+++ b/.azure/azure-pipelines.yml
@@ -35,11 +35,11 @@ steps:
       then
         sudo apt-get -y install libxcb-composite0-dev libx11-dev
       fi
-      curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain "stable"
+      curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain "1.39.0"
       export PATH=$HOME/.cargo/bin:$PATH
       rustc -Vv
       echo "##vso[task.prependpath]$HOME/.cargo/bin"
-      rustup component add rustfmt --toolchain "stable"
+      rustup component add rustfmt --toolchain "1.39.0"
     displayName: Install Rust
   - bash: RUSTFLAGS="-D warnings" cargo test --all-features
     condition: eq(variables['style'], 'unflagged')
diff --git a/docker/Dockerfile.nu-base b/docker/Dockerfile.nu-base
index 81e4822994..ca3ce44f23 100644
--- a/docker/Dockerfile.nu-base
+++ b/docker/Dockerfile.nu-base
@@ -12,7 +12,7 @@ RUN apt-get update && apt-get install -y libssl-dev \
 ARG RELEASE=false
 WORKDIR /code
 COPY ./rust-toolchain ./rust-toolchain
-RUN curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain "stable"
+RUN curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain "1.39.0"
 ENV PATH=/root/.cargo/bin:$PATH
 COPY . /code
 RUN echo "##vso[task.prependpath]/root/.cargo/bin" && \
diff --git a/rust-toolchain b/rust-toolchain
deleted file mode 100644
index 5edffce6d5..0000000000
--- a/rust-toolchain
+++ /dev/null
@@ -1 +0,0 @@
-1.39.0