diff --git a/src/applications/diffusion/request/git/DiffusionGitRequest.php b/src/applications/diffusion/request/git/DiffusionGitRequest.php
index 82b244ea38..2232cb1996 100644
--- a/src/applications/diffusion/request/git/DiffusionGitRequest.php
+++ b/src/applications/diffusion/request/git/DiffusionGitRequest.php
@@ -62,7 +62,7 @@ class DiffusionGitRequest extends DiffusionRequest {
           $this->commit);
 
         // Beyond verifying them, expand commit short forms to full 40-character
-        // sha1s.
+        // hashes.
         $this->commit = trim($commit);
 
         // If we have a commit, overwrite the branch commit with the more
diff --git a/src/storage/connection/isolated/__tests__/AphrontIsolatedDatabaseConnectionTestCase.php b/src/storage/connection/isolated/__tests__/AphrontIsolatedDatabaseConnectionTestCase.php
index dbed341c2f..e92aef2150 100644
--- a/src/storage/connection/isolated/__tests__/AphrontIsolatedDatabaseConnectionTestCase.php
+++ b/src/storage/connection/isolated/__tests__/AphrontIsolatedDatabaseConnectionTestCase.php
@@ -31,7 +31,7 @@ class AphrontIsolatedDatabaseConnectionTestCase
   public function testIsolation() {
     $conn = $this->newIsolatedConnection();
 
-    $test_phid = 'PHID-TEST-'.sha1(mt_rand());
+    $test_phid = 'PHID-TEST-'.Filesystem::readRandomCharacters(20);
 
     queryfx(
       $conn,
diff --git a/src/storage/connection/isolated/__tests__/__init__.php b/src/storage/connection/isolated/__tests__/__init__.php
index ce36833299..01b64ad096 100644
--- a/src/storage/connection/isolated/__tests__/__init__.php
+++ b/src/storage/connection/isolated/__tests__/__init__.php
@@ -11,6 +11,7 @@ phutil_require_module('phabricator', 'infrastructure/testing/testcase');
 phutil_require_module('phabricator', 'storage/connection/isolated');
 phutil_require_module('phabricator', 'storage/queryfx');
 
+phutil_require_module('phutil', 'filesystem');
 phutil_require_module('phutil', 'utils');