diff --git a/src/applications/conduit/controller/PhabricatorConduitAPIController.php b/src/applications/conduit/controller/PhabricatorConduitAPIController.php
--- a/src/applications/conduit/controller/PhabricatorConduitAPIController.php
+++ b/src/applications/conduit/controller/PhabricatorConduitAPIController.php
@@ -683,7 +683,7 @@
     // Otherwise, look for a single parameter called 'params' which has the
     // entire param dictionary JSON encoded.
     $params_json = $request->getStr('params');
-    if (strlen($params_json)) {
+    if (phutil_nonempty_string($params_json)) {
       $params = null;
       try {
         $params = phutil_json_decode($params_json);