diff --git a/.gitea/workflows/port-to-omp.yml b/.gitea/workflows/port-to-omp.yml
index c8f0186..fd653f2 100644
--- a/.gitea/workflows/port-to-omp.yml
+++ b/.gitea/workflows/port-to-omp.yml
@@ -32,6 +32,10 @@ jobs:
           OMP_REPO: omp-deepi-research
         run: |
           set -euo pipefail
+          # Trim the secret: a stray newline from pasting silently breaks
+          # oauth2 basic-auth. Fail loudly when it is missing entirely.
+          PORTING_TOKEN="$(printf '%s' "${PORTING_TOKEN}" | tr -d '[:space:]')"
+          : "${PORTING_TOKEN:?PORTING_TOKEN secret is not set}"
           URL="https://oauth2:${PORTING_TOKEN}@git.freno.me/Mike/${OMP_REPO}.git"
           # The omp checkout lives in $RUNNER_TEMP, outside the pi checkout:
           # the port script refuses to write into a subdirectory of its own