diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 742791b0..386e2204 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,9 +16,9 @@ jobs:
         submodules: true
 
     - name: Set up Ruby 2.7
-      uses: actions/setup-ruby@v1
+      uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 2.7.x
+        ruby-version: 2.7.0
 
     - name: Install Bundler
       run: gem install bundler
@@ -29,7 +29,7 @@ jobs:
         key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}
         restore-keys: |
           ${{ runner.os }}-gems-
-    
+
     - name: Bundle install
       run: |
         bundle config path vendor/bundle
diff --git a/_includes/first_application_common/pingpong_logic.md b/_includes/first_application_common/pingpong_logic.md
index f82731a1..72490952 100644
--- a/_includes/first_application_common/pingpong_logic.md
+++ b/_includes/first_application_common/pingpong_logic.md
@@ -11,4 +11,4 @@ with a `pong`. To test that this logic is correctly functioning, we implement co
 
 The diagram below clarifies the communication flow between these entities:
 
-![pingpong](http://www.plantuml.com/plantuml/png/ZOwnIWGn48RxFCNFzSkoUG2vqce5jHEHi1dtWZkPa6GByNntavZY10yknMJu-ORlFwPiOjvvK-d3-M2YOR1uMKvHc93ZJafvoMML07d7h1NAE-DPWblg_na8vnwEx9OeZmzFOt1-BK7AzetJciPxCfRYVw1S0SbRLBEg1IpXPIvpUWLCmZpXIm6BS3addt7uQpu0ZQlxT1MK2r0g-7sfqbsbRrVfMrMwgbev3CDTlsqJGtJhATUmSMrMg5TKwaZUxfcttuMt7m00)
\ No newline at end of file
+![pingpong](https://www.plantuml.com/plantuml/png/ZOv1IyGm48Nl-HMFlPVI_W3PewSAwar4GZjsWvrCIAO7SVtlTc8FAxYmbydZyONl7Olwh2ilhdo4c7ps39OeuoaB4pIlv5oKYV0oRBTx1Np1qE7B0QDmaaXHSMWvZ5aU7vxQ5E9y02fdkRiAoWKe1dvVglfTrT-kwczLzQQguz0qT_lVUj7aC9_KoihLMw4wqGOgGIL1tZ6O43ZZML8OxVrCXFDU_jsv5KMdDovpQU_9JvJ_0-KAI762cPqxRd5LNdu3Bpy0)
\ No newline at end of file