diff --git a/ci/request-reviews/process-reviewers.sh b/ci/request-reviews/process-reviewers.sh
index b70a1a7fc4519..e1051cdc93cfb 100755
--- a/ci/request-reviews/process-reviewers.sh
+++ b/ci/request-reviews/process-reviewers.sh
@@ -19,11 +19,13 @@ baseRepo=$1
 prNumber=$2
 prAuthor=$3
 
+org=${baseRepo%%/*}
+
 tmp=$(mktemp -d)
 trap 'rm -rf "$tmp"' exit
 
 declare -A users=()
-while read -r handle; do
+while read -r handle && [[ -n "$handle" ]]; do
     users[$handle]=
 done
 
@@ -47,6 +49,16 @@ while read -r user; do
     fi
 done < "$tmp/already-reviewed-by"
 
+for user in "${!users[@]}"; do
+    if ! gh api \
+        -H "Accept: application/vnd.github+json" \
+        -H "X-GitHub-Api-Version: 2022-11-28" \
+        "/orgs/$org/members/$user" >&2; then
+        log "User $user is not part of the $org org, probably missed the automated invite (see https://github.com/NixOS/nixpkgs/issues/234293), ignoring.."
+        unset 'users[$user]'
+    fi
+done
+
 # Turn it into a JSON for the GitHub API call to request PR reviewers
 jq -n \
     --arg users "${!users[*]}" \