diff --git a/stdlib/public/BackDeployConcurrency/CMakeLists.txt b/stdlib/public/BackDeployConcurrency/CMakeLists.txt
index 646f968c0654a..9e33f1809056e 100644
--- a/stdlib/public/BackDeployConcurrency/CMakeLists.txt
+++ b/stdlib/public/BackDeployConcurrency/CMakeLists.txt
@@ -66,4 +66,4 @@ set(LLVM_OPTIONAL_SOURCES
   TaskSleepDuration.swift)
 
 add_subdirectory(../Concurrency stdlib/public/BackDeployConcurrency)
-add_subdirectory(../Threading stdlib/public/BackDeployConcurrency)
+add_subdirectory(../Threading)