diff --git a/libc/test/UnitTest/CMakeLists.txt b/libc/test/UnitTest/CMakeLists.txt
--- a/libc/test/UnitTest/CMakeLists.txt
+++ b/libc/test/UnitTest/CMakeLists.txt
@@ -37,6 +37,7 @@
   )
 endforeach()
 
+target_include_directories(LibcHermeticTest PRIVATE ${LIBC_BUILD_DIR}/include)
 target_compile_options(LibcHermeticTest PRIVATE -ffreestanding -nostdlib -nostdlib++)
 
 add_library(