diff --git a/.github/workflows/verify-on-macos.yml b/.github/workflows/verify-on-macos.yml
index ad7454f..df3da7d 100644
--- a/.github/workflows/verify-on-macos.yml
+++ b/.github/workflows/verify-on-macos.yml
@@ -14,6 +14,8 @@ jobs:
         known-hosts: ${{ secrets.KNOWN_HOSTS }} # optional
     - name: print created files
       run: ls -l ~/.ssh
+    - name: SSH to github.com
+      run: ssh -v git@github.com
     - name: git clone through SSH
       run: git clone git@github.com:shimataro/ssh-key-action.git tmp
   ssh-with-name:
@@ -33,5 +35,7 @@ jobs:
             IdentityFile ~/.ssh/ssh_key_name
     - name: print created files
       run: ls -l ~/.ssh
+    - name: SSH to github.com
+      run: ssh -v git@github.com
     - name: git clone through SSH
       run: git clone github:shimataro/ssh-key-action.git tmp
diff --git a/.github/workflows/verify-on-ubuntu.yml b/.github/workflows/verify-on-ubuntu.yml
index 98c240b..c65b045 100644
--- a/.github/workflows/verify-on-ubuntu.yml
+++ b/.github/workflows/verify-on-ubuntu.yml
@@ -14,6 +14,8 @@ jobs:
         known-hosts: ${{ secrets.KNOWN_HOSTS }} # optional
     - name: print created files
       run: ls -l ~/.ssh
+    - name: SSH to github.com
+      run: ssh -v git@github.com
     - name: git clone through SSH
       run: git clone git@github.com:shimataro/ssh-key-action.git tmp
   ssh-with-name:
@@ -33,5 +35,7 @@ jobs:
             IdentityFile ~/.ssh/ssh_key_name
     - name: print created files
       run: ls -l ~/.ssh
+    - name: SSH to github.com
+      run: ssh -v git@github.com
     - name: git clone through SSH
       run: git clone github:shimataro/ssh-key-action.git tmp
diff --git a/.github/workflows/verify-on-ubuntu1604.yml b/.github/workflows/verify-on-ubuntu1604.yml
index bb3ccc5..30d025c 100644
--- a/.github/workflows/verify-on-ubuntu1604.yml
+++ b/.github/workflows/verify-on-ubuntu1604.yml
@@ -14,6 +14,8 @@ jobs:
         known-hosts: ${{ secrets.KNOWN_HOSTS }} # optional
     - name: print created files
       run: ls -l ~/.ssh
+    - name: SSH to github.com
+      run: ssh -v git@github.com
     - name: git clone through SSH
       run: git clone git@github.com:shimataro/ssh-key-action.git tmp
   ssh-with-name:
@@ -33,5 +35,7 @@ jobs:
             IdentityFile ~/.ssh/ssh_key_name
     - name: print created files
       run: ls -l ~/.ssh
+    - name: SSH to github.com
+      run: ssh -v git@github.com
     - name: git clone through SSH
       run: git clone github:shimataro/ssh-key-action.git tmp
diff --git a/.github/workflows/verify-on-windows.yml b/.github/workflows/verify-on-windows.yml
index e76ce83..2f1146f 100644
--- a/.github/workflows/verify-on-windows.yml
+++ b/.github/workflows/verify-on-windows.yml
@@ -14,6 +14,8 @@ jobs:
         known-hosts: ${{ secrets.KNOWN_HOSTS }} # optional
     - name: print created files
       run: ls ~/.ssh
+    - name: SSH to github.com
+      run: ssh -v git@github.com
     - name: git clone through SSH
       run: git clone git@github.com:shimataro/ssh-key-action.git tmp
   ssh-with-name:
@@ -33,5 +35,7 @@ jobs:
             IdentityFile ~/.ssh/ssh_key_name
     - name: print created files
       run: ls ~/.ssh
+    - name: SSH to github.com
+      run: ssh -v git@github.com
     - name: git clone through SSH
       run: git clone github:shimataro/ssh-key-action.git tmp