diff --git a/src/lint/linter/ArcanistLinter.php b/src/lint/linter/ArcanistLinter.php
--- a/src/lint/linter/ArcanistLinter.php
+++ b/src/lint/linter/ArcanistLinter.php
@@ -230,7 +230,8 @@
     if (!$this->getEngine()->getCommitHookMode()) {
       $root = $this->getEngine()->getWorkingCopy()->getProjectRoot();
       $path = Filesystem::resolvePath($message->getPath(), $root);
-      $message->setPath(Filesystem::readablePath($path, $root));
+      $path = Filesystem::readablePath($path, $root);
+      $message->setPath(str_replace(DIRECTORY_SEPARATOR, '/', $path));
     }
     $this->messages[] = $message;
     return $message;