diff --git a/scripts/daemon/launch_daemon.php b/scripts/daemon/launch_daemon.php
--- a/scripts/daemon/launch_daemon.php
+++ b/scripts/daemon/launch_daemon.php
@@ -20,6 +20,11 @@
   $flags[] = '--load-phutil-library='.phutil_get_library_root($library);
 }
 
+$umask_octal = PhabricatorEnv::getEnvConfig('phd.umask');
+if (! empty($umask_octal)) {
+  umask(octdec($umask_octal));
+}
+
 // Add more flags.
 array_splice($argv, 2, 0, $flags);
 
diff --git a/src/applications/config/option/PhabricatorPHDConfigOptions.php b/src/applications/config/option/PhabricatorPHDConfigOptions.php
--- a/src/applications/config/option/PhabricatorPHDConfigOptions.php
+++ b/src/applications/config/option/PhabricatorPHDConfigOptions.php
@@ -49,6 +49,13 @@
             "of output, but can help debug issues. Daemons launched in debug ".
             "mode with 'phd debug' are always launched in verbose mode. See ".
             "also 'phd.trace'.")),
+      $this->newOption('phd.umask', 'string', null)
+        ->setLocked(true)
+        ->setSummary(pht('Process umask for phd daemons'))
+        ->setDescription(
+          pht(
+            'Specify the phd daemon umask to override systems umask.'.
+            'Examples: 077, 027, 007')),
       $this->newOption('phd.user', 'string', null)
         ->setLocked(true)
         ->setSummary(pht('System user to run daemons as.'))