diff --git a/src/applications/conduit/management/PhabricatorConduitCallManagementWorkflow.php b/src/applications/conduit/management/PhabricatorConduitCallManagementWorkflow.php
index a12d1374dc..f2ddddd848 100644
--- a/src/applications/conduit/management/PhabricatorConduitCallManagementWorkflow.php
+++ b/src/applications/conduit/management/PhabricatorConduitCallManagementWorkflow.php
@@ -1,107 +1,107 @@
 <?php
 
 final class PhabricatorConduitCallManagementWorkflow
   extends PhabricatorConduitManagementWorkflow {
 
   protected function didConstruct() {
     $this
       ->setName('call')
       ->setSynopsis(pht('Call a Conduit method..'))
       ->setArguments(
         array(
           array(
             'name' => 'method',
             'param' => 'method',
             'help' => pht('Method to call.'),
           ),
           array(
             'name' => 'input',
             'param' => 'input',
             'help' => pht(
               'File to read parameters from, or "-" to read from '.
               'stdin.'),
           ),
           array(
             'name' => 'local',
             'help' => pht(
               'Force the request to execute in this process, rather than '.
               'proxying to another host in the cluster.'),
           ),
           array(
             'name' => 'as',
             'param' => 'username',
             'help' => pht(
               'Execute the call as the given user. (If omitted, the call will '.
               'be executed as an omnipotent user.)'),
           ),
         ));
   }
 
   public function execute(PhutilArgumentParser $args) {
     $viewer = $this->getViewer();
 
     $method = $args->getArg('method');
-    if (!strlen($method)) {
+    if (!phutil_nonempty_string($method)) {
       throw new PhutilArgumentUsageException(
         pht('Specify a method to call with "--method".'));
     }
 
     $input = $args->getArg('input');
-    if (!strlen($input)) {
+    if (!phutil_nonempty_string($input)) {
       throw new PhutilArgumentUsageException(
         pht('Specify a file to read parameters from with "--input".'));
     }
 
     $as = $args->getArg('as');
-    if (strlen($as)) {
+    if (phutil_nonempty_string($as)) {
       $actor = id(new PhabricatorPeopleQuery())
         ->setViewer($viewer)
         ->withUsernames(array($as))
         ->executeOne();
       if (!$actor) {
         throw new PhutilArgumentUsageException(
           pht(
             'No such user "%s" exists.',
             $as));
       }
 
       // Allow inline generation of user caches for the user we're acting
       // as, since some calls may read user preferences.
       $actor->setAllowInlineCacheGeneration(true);
     } else {
       $actor = $viewer;
     }
 
     if ($input === '-') {
       fprintf(STDERR, tsprintf("%s\n", pht('Reading input from stdin...')));
       $input_json = file_get_contents('php://stdin');
     } else {
       $input_json = Filesystem::readFile($input);
     }
 
     $params = phutil_json_decode($input_json);
 
     $call = id(new ConduitCall($method, $params))
       ->setUser($actor);
 
     $api_request = $call->getAPIRequest();
 
     $is_local = $args->getArg('local');
     if ($is_local) {
       $api_request->setIsClusterRequest(true);
     }
 
     $result = $call->execute();
 
     $output = array(
       'result' => $result,
     );
 
     echo tsprintf(
       "%B\n",
       id(new PhutilJSON())->encodeFormatted($output));
 
     return 0;
   }
 
 }