diff --git a/.github/workflows/deploy-dev.yaml b/.github/workflows/deploy-dev.yaml
index 65b79022..12224d04 100644
--- a/.github/workflows/deploy-dev.yaml
+++ b/.github/workflows/deploy-dev.yaml
@@ -87,7 +87,17 @@ jobs:
             DEPLOY_CMD="reset-zkcoins-node"
           fi
 
+          # ServerAlive* keep the session alive across long-running
+          # `docker compose recreate` steps where the remote command
+          # produces no stdout for >60s. Without keepalive the
+          # cloudflared tunnel (and the OpenSSH client) drop the
+          # session and exit 255 even though the host-side deploy
+          # script keeps running — observed on the PR #111 merge
+          # (run 26419696840). 30s interval × 8 retries = 4 min of
+          # network silence tolerated before the session is killed.
           ssh -i ~/.ssh/deploy_key \
+            -o ServerAliveInterval=30 \
+            -o ServerAliveCountMax=8 \
             -o ProxyCommand="cloudflared access ssh --hostname ${{ secrets.DEPLOY_DEV_HOST }}" \
             ${{ secrets.DEPLOY_DEV_USER }}@${{ secrets.DEPLOY_DEV_HOST }} \
             "$DEPLOY_CMD"
diff --git a/.github/workflows/deploy-prd.yaml b/.github/workflows/deploy-prd.yaml
index 3257b9a1..8af19ffe 100644
--- a/.github/workflows/deploy-prd.yaml
+++ b/.github/workflows/deploy-prd.yaml
@@ -63,7 +63,15 @@ jobs:
           echo "${{ secrets.DEPLOY_PRD_SSH_KEY }}" > ~/.ssh/deploy_key
           chmod 600 ~/.ssh/deploy_key
           echo "${{ secrets.DEPLOY_PRD_SSH_KNOWN_HOSTS }}" > ~/.ssh/known_hosts
+          # ServerAlive* keep the session alive across long-running
+          # `docker compose recreate` steps where the remote command
+          # produces no stdout for >60s. Mirrors deploy-dev.yaml; see
+          # the comment there for the failure mode that motivated this
+          # (PR #111 merge run 26419696840 — SSH dropped mid-recreate,
+          # exit 255, container actually came up server-side).
           ssh -i ~/.ssh/deploy_key \
+            -o ServerAliveInterval=30 \
+            -o ServerAliveCountMax=8 \
             -o ProxyCommand="cloudflared access ssh --hostname ${{ secrets.DEPLOY_PRD_HOST }}" \
             ${{ secrets.DEPLOY_PRD_USER }}@${{ secrets.DEPLOY_PRD_HOST }} \
             "zkcoins-node"