diff --git a/Library/Homebrew/dev-cmd/test.rb b/Library/Homebrew/dev-cmd/test.rb
index 1e74496dc5..7eadd67598 100644
--- a/Library/Homebrew/dev-cmd/test.rb
+++ b/Library/Homebrew/dev-cmd/test.rb
@@ -87,6 +87,7 @@ module Homebrew
             sandbox.allow_write_log(f)
             sandbox.allow_write_xcode
             sandbox.allow_write_path(HOMEBREW_PREFIX/"var/cache")
+            sandbox.allow_write_path(HOMEBREW_PREFIX/"var/homebrew/locks")
             sandbox.allow_write_path(HOMEBREW_PREFIX/"var/log")
             sandbox.allow_write_path(HOMEBREW_PREFIX/"var/run")
             sandbox.exec(*args)