diff --git a/atst/routes/__init__.py b/atst/routes/__init__.py
index 0ea12952..214fb35c 100644
--- a/atst/routes/__init__.py
+++ b/atst/routes/__init__.py
@@ -97,8 +97,10 @@ def _make_authentication_context():
 def redirect_after_login_url():
     if request.args.get("next"):
         returl = request.args.get("next")
-        if request.args.get("formCache"):
-            returl += "?" + url.urlencode({"formCache": request.args.get("formCache")})
+        if request.args.get(app.form_cache.PARAM_NAME):
+            returl += "?" + url.urlencode(
+                {app.form_cache.PARAM_NAME: request.args.get(app.form_cache.PARAM_NAME)}
+            )
         return returl
     else:
         return url_for("atst.home")
diff --git a/atst/routes/errors.py b/atst/routes/errors.py
index 039ae635..3f32b110 100644
--- a/atst/routes/errors.py
+++ b/atst/routes/errors.py
@@ -39,7 +39,7 @@ def make_error_pages(app):
         log_error(e)
         url_args = {"sessionExpired": True, "next": request.path}
         if request.method == "POST":
-            url_args["formCache"] = app.form_cache.write(request.form)
+            url_args[app.form_cache.PARAM_NAME] = app.form_cache.write(request.form)
         return redirect(url_for("atst.root", **url_args))
 
     @app.errorhandler(Exception)
diff --git a/atst/utils/form_cache.py b/atst/utils/form_cache.py
index 3ce4f17a..c7ac6d80 100644
--- a/atst/utils/form_cache.py
+++ b/atst/utils/form_cache.py
@@ -7,11 +7,13 @@ DEFAULT_CACHE_NAME = "formcache"
 
 
 class FormCache(object):
+    PARAM_NAME = "formCache"
+
     def __init__(self, redis):
         self.redis = redis
 
     def from_request(self, http_request):
-        cache_key = http_request.args.get("formCache")
+        cache_key = http_request.args.get(self.PARAM_NAME)
         if cache_key:
             return self.read(cache_key)