diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index c58c50f..a81a4cc 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -16,17 +16,15 @@ jobs:
         mkdir mdbook
         curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.14/mdbook-v0.4.14-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
         echo `pwd`/mdbook >> $GITHUB_PATH
-    - name: Install plantuml
-      run: sudo apt-get install plantuml
     - name: Install Rust
       uses: actions-rs/toolchain@v1
       with:
         toolchain: stable
-    - name: Install mdbook-plantuml
+    - name: Install mdbook-yapp 
       uses: actions-rs/cargo@v1
       with:
         command: install
-        args: mdbook-plantuml
+        args: mdbook-yapp
     - name: Deploy GitHub Pages
       run: |
         # This assumes your book is in the root of your repository.
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c87927c..0131f30 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,17 +14,15 @@ jobs:
         mkdir mdbook
         curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.14/mdbook-v0.4.14-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
         echo `pwd`/mdbook >> $GITHUB_PATH
-    - name: Install plantuml
-      run: sudo apt-get install plantuml
     - name: Install Rust
       uses: actions-rs/toolchain@v1
       with:
         toolchain: stable
-    - name: Install mdbook-plantuml
+    - name: Install mdbook-yapp 
       uses: actions-rs/cargo@v1
       with:
         command: install
-        args: mdbook-plantuml
+        args: mdbook-yapp
     - name: Deploy GitHub Pages
       run: mdbook build