diff --git a/.github/workflows/deploy-docs.yml b/.github/workflows/deploy-docs.yml
index a55791dfa..08cd82067 100644
--- a/.github/workflows/deploy-docs.yml
+++ b/.github/workflows/deploy-docs.yml
@@ -37,6 +37,7 @@ jobs:
         env:
           GH_TOKEN: ${{ github.token }}
           WORKFLOW_RUN_ID: ${{ github.event.workflow_run.id }}
+          WORKFLOW_HEAD_SHA: ${{ github.event.workflow_run.head_sha }}
         run: |
           set -euo pipefail
 
@@ -67,24 +68,40 @@ jobs:
             pr_number="${metadata_pr_number}"
           fi
 
+          if [ "${metadata_action}" != "closed" ] && [ "${has_preview_artifact}" != "true" ]; then
+            echo "No current preview deploy or cleanup target found for workflow run ${WORKFLOW_RUN_ID}."
+            echo "mode=none" >> "${GITHUB_OUTPUT}"
+            exit 0
+          fi
+
+          if ! [[ "${pr_number}" =~ ^[0-9]+$ ]]; then
+            echo "No pull request number found for workflow run ${GITHUB_RUN_ID}."
+            exit 1
+          fi
+
           mode="none"
           if [ "${metadata_action}" = "closed" ]; then
             mode="cleanup"
           elif [ "${has_preview_artifact}" = "true" ]; then
-            mode="deploy"
+            pr_json="$(gh api "repos/${GITHUB_REPOSITORY}/pulls/${pr_number}")"
+            pr_state="$(jq -r '.state' <<< "${pr_json}")"
+            pr_head_sha="$(jq -r '.head.sha' <<< "${pr_json}")"
+
+            if [ "${pr_state}" != "open" ]; then
+              echo "PR #${pr_number} is ${pr_state}; removing preview instead of deploying stale artifact."
+              mode="cleanup"
+            elif [ "${pr_head_sha}" != "${WORKFLOW_HEAD_SHA}" ]; then
+              echo "Workflow run ${WORKFLOW_RUN_ID} is for ${WORKFLOW_HEAD_SHA}, but PR #${pr_number} is now at ${pr_head_sha}; skipping stale preview deploy."
+            else
+              mode="deploy"
+            fi
           fi
 
           if [ "${mode}" = "none" ]; then
-            echo "No preview or cleanup artifact found for workflow run ${WORKFLOW_RUN_ID}."
             echo "mode=none" >> "${GITHUB_OUTPUT}"
             exit 0
           fi
 
-          if ! [[ "${pr_number}" =~ ^[0-9]+$ ]]; then
-            echo "No pull request number found for workflow run ${GITHUB_RUN_ID}."
-            exit 1
-          fi
-
           preview_path="preview/pr-${pr_number}/"
           preview_url="https://vide.pascal-lab.net/${preview_path}"