diff --git a/scripts/setup-desktop.sh b/scripts/setup-desktop.sh
index 32887aa1..8db18518 100755
--- a/scripts/setup-desktop.sh
+++ b/scripts/setup-desktop.sh
@@ -21,8 +21,11 @@ sudo DEBIAN_FRONTEND=noninteractive apt install -y -qq \
   ubuntu-desktop \
   gdm3 \
   x11vnc \
+  tigervnc-common \
   dbus-x11
 echo "  Done."
+# tigervnc-common provides `vncpasswd`, which the VNC sidecar uses to write the .vnc/passwd rfbauth
+# file that x11vnc mirrors :0 with (see vnc-manager.ts). x11vnc alone does NOT ship vncpasswd.
 
 # --- Step 2: Force GDM onto Xorg + enable auto-login (x11vnc cannot mirror Wayland) ---
 echo "[2/5] Forcing Xorg session and auto-login in GDM..."