diff --git a/.github/workflows/contrib.yml b/.github/workflows/contrib.yml
index ee1529194c4..bbd4a7ef7ff 100644
--- a/.github/workflows/contrib.yml
+++ b/.github/workflows/contrib.yml
@@ -19,7 +19,7 @@ jobs:
     - name: Install mdbook
       run: |
         mkdir mdbook
-        curl -Lf https://github.com/rust-lang/mdBook/releases/download/v0.4.26/mdbook-v0.4.26-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
+        curl -Lf https://github.com/rust-lang/mdBook/releases/download/v0.4.27/mdbook-v0.4.27-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
         echo `pwd`/mdbook >> $GITHUB_PATH
     - name: Deploy docs
       run: |
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 861c0a9ed92..a58992d52ec 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -170,7 +170,7 @@ jobs:
     - run: cd src/doc/semver-check && cargo +stable run
     - run: |
         mkdir mdbook
-        curl -Lf https://github.com/rust-lang/mdBook/releases/download/v0.4.5/mdbook-v0.4.5-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
+        curl -Lf https://github.com/rust-lang/mdBook/releases/download/v0.4.27/mdbook-v0.4.27-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
         echo `pwd`/mdbook >> $GITHUB_PATH
     - run: cargo doc --document-private-items --no-deps
       env: