diff --git a/scripts/ssh/ssh-connect.php b/scripts/ssh/ssh-connect.php
index f02bafb936..639a319947 100755
--- a/scripts/ssh/ssh-connect.php
+++ b/scripts/ssh/ssh-connect.php
@@ -1,43 +1,48 @@
 #!/usr/bin/env php
 <?php
 
 // This is a wrapper script for Git, Mercurial, and Subversion. It primarily
 // serves to inject "-o StrictHostKeyChecking=no" into the SSH arguments.
 
 $root = dirname(dirname(dirname(__FILE__)));
 require_once $root.'/scripts/__init_script__.php';
 
 $pattern = array();
 $arguments = array();
 
 $pattern[] = 'ssh';
 
 $pattern[] = '-o';
 $pattern[] = 'StrictHostKeyChecking=no';
 
+// This prevents "known host" failures, and covers for issues where HOME is set
+// to something unusual.
+$pattern[] = '-o';
+$pattern[] = 'UserKnownHostsFile=/dev/null';
+
 $credential_phid = getenv('PHABRICATOR_CREDENTIAL');
 if ($credential_phid) {
   $viewer = PhabricatorUser::getOmnipotentUser();
   $key = PassphraseSSHKey::loadFromPHID($credential_phid, $viewer);
 
   $pattern[] = '-l %P';
   $arguments[] = $key->getUsernameEnvelope();
   $pattern[] = '-i %P';
   $arguments[] = $key->getKeyfileEnvelope();
 }
 
 $pattern[] = '--';
 
 $passthru_args = array_slice($argv, 1);
 foreach ($passthru_args as $passthru_arg) {
   $pattern[] = '%s';
   $arguments[] = $passthru_arg;
 }
 
 $pattern = implode(' ', $pattern);
 array_unshift($arguments, $pattern);
 
 $err = newv('PhutilExecPassthru', $arguments)
   ->execute();
 
 exit($err);