diff --git a/nixos/modules/services/misc/nixos-manual.nix b/nixos/modules/services/misc/nixos-manual.nix
index 3916c3052e8b..993b59590bb0 100644
--- a/nixos/modules/services/misc/nixos-manual.nix
+++ b/nixos/modules/services/misc/nixos-manual.nix
@@ -44,7 +44,13 @@ let
   helpScript = pkgs.writeScriptBin "nixos-help"
     ''
       #! ${pkgs.runtimeShell} -e
-      browser="$BROWSER"
+      # Finds first executable browser in a colon-separated list.
+      # (see how xdg-open defines BROWSER)
+      browser="$(
+        IFS=: ; for b in $BROWSER; do
+          [ -n "$(type -P "$b" || true)" ] && echo "$b" && break
+        done
+      )"
       if [ -z "$browser" ]; then
         browser="$(type -P xdg-open || true)"
         if [ -z "$browser" ]; then