diff --git a/nixos/modules/installer/tools/nixos-rebuild.sh b/nixos/modules/installer/tools/nixos-rebuild.sh
index 1d6df8cb3f7..ccafa30856c 100644
--- a/nixos/modules/installer/tools/nixos-rebuild.sh
+++ b/nixos/modules/installer/tools/nixos-rebuild.sh
@@ -96,6 +96,14 @@ fi
 # If ‘--upgrade’ is given, run ‘nix-channel --update nixos’.
 if [ -n "$upgrade" -a -z "$_NIXOS_REBUILD_REEXEC" ]; then
     nix-channel --update nixos
+
+    # If there are other channels that contain a file called
+    # ".update-on-nixos-rebuild", update them as well.
+    for channelpath in /nix/var/nix/profiles/per-user/root/channels/*; do
+        if [ -e "$channelpath/.update-on-nixos-rebuild" ]; then
+            nix-channel --update "$(basename "$channelpath")"
+        fi
+    done
 fi
 
 # Make sure that we use the Nix package we depend on, not something
diff --git a/nixos/modules/programs/environment.nix b/nixos/modules/programs/environment.nix
index e0379a2c02a..dce757ceb62 100644
--- a/nixos/modules/programs/environment.nix
+++ b/nixos/modules/programs/environment.nix
@@ -28,6 +28,7 @@ in
           [ "/nix/var/nix/profiles/per-user/root/channels/nixos"
             "nixpkgs=/etc/nixos/nixpkgs"
             "nixos-config=/etc/nixos/configuration.nix"
+            "/nix/var/nix/profiles/per-user/root/channels"
           ];
       };