diff --git a/conf.py b/conf.py
index c1ad471b..73837c1b 100644
--- a/conf.py
+++ b/conf.py
@@ -23,6 +23,12 @@
 author = "Gravwell, Inc."
 release = "v5.4.3"
 
+# Default to localhost:8000, so the version switcher looks OK on livehtml
+version_list_url = os.environ.get(
+    "VERSION_LIST_URL", "http://localhost:8000/_static/versions.json"
+)
+print("Using version_list_url:", version_list_url)
+
 # -- General configuration ---------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
 
@@ -96,7 +102,7 @@
     # Version switcher
     #
     "switcher": {
-        "json_url": "https://docs.gravwell.io/_static/versions.json",
+        "json_url": version_list_url,
         # The `version` field of each entry in verions.json must match a vN.N.N release name
         "version_match": release,
     },
diff --git a/default.nix b/default.nix
index 9b527c99..ebc30c39 100644
--- a/default.nix
+++ b/default.nix
@@ -1,3 +1,4 @@
+{ VERSION_LIST_URL ? null }:
 let
   # use a specific (although arbitrarily chosen) version of the Nix package collection
   pkgs = import (fetchTarball {
@@ -66,6 +67,8 @@ in pkgs.stdenv.mkDerivation {
   name = "gravwell-wiki";
   src = ./.;
 
+  VERSION_LIST_URL = VERSION_LIST_URL;
+
   buildInputs = [ pythonBundle pkgs.gnumake pkgs.git custom-aspell ];
   buildPhase = ''
     make clean html