diff --git a/ssh_router.sh b/ssh_router.sh
index e0efab7..b2245bf 100755
--- a/ssh_router.sh
+++ b/ssh_router.sh
@@ -12,6 +12,12 @@ log() {
   echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" >>"$LOG_FILE"
 }
 
+if [[ ! -t 0 ]]; then
+  log "❌ No TTY allocated — refusing to run tmux without an interactive terminal"
+  echo "Error: No TTY. Use 'ssh -t'" >&2
+  exit 1
+fi
+
 # log "🧩 IMAGE = '$IMAGE'"
 # log "🧩 WORKSPACE = '$WORKSPACE'"
 # log "🧩 PERSON = '$PERSON'"