diff --git a/src/cache/PhutilKeyValueCacheDirectory.php b/src/cache/PhutilKeyValueCacheDirectory.php
--- a/src/cache/PhutilKeyValueCacheDirectory.php
+++ b/src/cache/PhutilKeyValueCacheDirectory.php
@@ -98,7 +98,7 @@
         if (!Filesystem::pathExists($key_dir)) {
           Filesystem::createDirectory(
             $key_dir,
-            $mask = 0777,
+            $mask = 0755,
             $recursive = true);
         }
 
@@ -215,7 +215,7 @@
     }
 
     if (!Filesystem::pathExists($this->getCacheDirectory())) {
-      Filesystem::createDirectory($this->getCacheDirectory(), 0777, true);
+      Filesystem::createDirectory($this->getCacheDirectory(), 0755, true);
     }
 
     $lock = PhutilFileLock::newForPath($this->getCacheDirectory().'.lock');