diff --git a/gnu/system/examples/asus-c201.tmpl b/gnu/system/examples/asus-c201.tmpl
index 6b6aa706fa..019111c167 100644
--- a/gnu/system/examples/asus-c201.tmpl
+++ b/gnu/system/examples/asus-c201.tmpl
@@ -1,3 +1,4 @@
+;; -*- mode: scheme; -*-
 ;; This is an operating system configuration template
 ;; for a "bare bones" setup for an ASUS C201PA.
 
diff --git a/gnu/system/examples/bare-bones.tmpl b/gnu/system/examples/bare-bones.tmpl
index 687d4c1573..45b4995574 100644
--- a/gnu/system/examples/bare-bones.tmpl
+++ b/gnu/system/examples/bare-bones.tmpl
@@ -1,3 +1,4 @@
+;; -*- mode: scheme; -*-
 ;; This is an operating system configuration template
 ;; for a "bare bones" setup, with no X11 display server.
 
diff --git a/gnu/system/examples/beaglebone-black.tmpl b/gnu/system/examples/beaglebone-black.tmpl
index 90dab62062..40d0a76a37 100644
--- a/gnu/system/examples/beaglebone-black.tmpl
+++ b/gnu/system/examples/beaglebone-black.tmpl
@@ -1,3 +1,4 @@
+;; -*- mode: scheme; -*-
 ;; This is an operating system configuration template
 ;; for a "bare bones" setup on BeagleBone Black board.
 
diff --git a/gnu/system/examples/desktop.tmpl b/gnu/system/examples/desktop.tmpl
index 7055a8f92d..10d0e54fa7 100644
--- a/gnu/system/examples/desktop.tmpl
+++ b/gnu/system/examples/desktop.tmpl
@@ -1,3 +1,4 @@
+;; -*- mode: scheme; -*-
 ;; This is an operating system configuration template
 ;; for a "desktop" setup with GNOME and Xfce where the
 ;; root partition is encrypted with LUKS, and a swap file.
diff --git a/gnu/system/examples/docker-image.tmpl b/gnu/system/examples/docker-image.tmpl
index bdc6afa6f0..7123917af4 100644
--- a/gnu/system/examples/docker-image.tmpl
+++ b/gnu/system/examples/docker-image.tmpl
@@ -1,3 +1,4 @@
+;; -*- mode: scheme; -*-
 ;; This is an operating system configuration template for a "Docker image"
 ;; setup, so it has barely any services at all.
 
diff --git a/gnu/system/examples/lightweight-desktop.tmpl b/gnu/system/examples/lightweight-desktop.tmpl
index d4330ecc8e..4cb3c38311 100644
--- a/gnu/system/examples/lightweight-desktop.tmpl
+++ b/gnu/system/examples/lightweight-desktop.tmpl
@@ -1,3 +1,4 @@
+;; -*- mode: scheme; -*-
 ;; This is an operating system configuration template
 ;; for a "desktop" setup without full-blown desktop
 ;; environments.
diff --git a/gnu/system/examples/raspberry-pi-64-nfs-root.tmpl b/gnu/system/examples/raspberry-pi-64-nfs-root.tmpl
index 8c47c650f6..2203375270 100644
--- a/gnu/system/examples/raspberry-pi-64-nfs-root.tmpl
+++ b/gnu/system/examples/raspberry-pi-64-nfs-root.tmpl
@@ -1,3 +1,4 @@
+;; -*- mode: scheme; -*-
 ;; This is an operating-system configuration template of a
 ;; 64-bit minimal system for a Raspberry Pi with an NFS root file-system.
 
diff --git a/gnu/system/examples/raspberry-pi-64.tmpl b/gnu/system/examples/raspberry-pi-64.tmpl
index 3ad588207c..185d25c412 100644
--- a/gnu/system/examples/raspberry-pi-64.tmpl
+++ b/gnu/system/examples/raspberry-pi-64.tmpl
@@ -1,3 +1,4 @@
+;; -*- mode: scheme; -*-
 ;; This is an operating-system configuration template of a
 ;; 64-bit minimal system for a Raspberry Pi with local storage.
 
diff --git a/gnu/system/examples/vm-image.tmpl b/gnu/system/examples/vm-image.tmpl
index d46a27978c..343287eaf6 100644
--- a/gnu/system/examples/vm-image.tmpl
+++ b/gnu/system/examples/vm-image.tmpl
@@ -1,3 +1,4 @@
+;; -*- mode: scheme; -*-
 ;; This is an operating system configuration for a VM image.
 ;; Modify it as you see fit and instantiate the changes by running:
 ;;