diff --git a/libc/cmake/modules/LLVMLibCRules.cmake b/libc/cmake/modules/LLVMLibCRules.cmake
--- a/libc/cmake/modules/LLVMLibCRules.cmake
+++ b/libc/cmake/modules/LLVMLibCRules.cmake
@@ -355,7 +355,7 @@
     ${LIBC_UNITTEST_DEPENDS}
   )
 
-  target_link_libraries(${target_name} PRIVATE LibcUnitTest)
+  target_link_libraries(${target_name} PRIVATE LibcUnitTest libc_test_utils)
 
   add_custom_command(
     TARGET ${target_name}
diff --git a/libc/utils/CMakeLists.txt b/libc/utils/CMakeLists.txt
--- a/libc/utils/CMakeLists.txt
+++ b/libc/utils/CMakeLists.txt
@@ -2,3 +2,4 @@
 add_subdirectory(HdrGen)
 add_subdirectory(UnitTest)
 add_subdirectory(benchmarks)
+add_subdirectory(testutils)
diff --git a/libc/utils/testutils/CMakeLists.txt b/libc/utils/testutils/CMakeLists.txt
new file mode 100644
--- /dev/null
+++ b/libc/utils/testutils/CMakeLists.txt
@@ -0,0 +1,12 @@
+
+add_library(
+  libc_test_utils
+  abort.cpp
+  Support.h
+  Thread.cpp
+  Thread.h
+)
+
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+  target_sources(libc_test_utils PRIVATE ${LIBC_TARGET_OS}/sleep.cpp)
+endif()
diff --git a/libc/utils/testutils/Support.h b/libc/utils/testutils/Support.h
new file mode 100644
--- /dev/null
+++ b/libc/utils/testutils/Support.h
@@ -0,0 +1,9 @@
+
+namespace __llvm_libc {
+namespace testutils {
+
+int sleep(unsigned int seconds);
+void abort();
+
+} // namespace testutils
+} // namespace __llvm_libc
diff --git a/libc/utils/testutils/Thread.h b/libc/utils/testutils/Thread.h
new file mode 100644
--- /dev/null
+++ b/libc/utils/testutils/Thread.h
@@ -0,0 +1,27 @@
+
+#ifndef LLVM_LIBC_UTILS_TESTING_THREAD_H
+#define LLVM_LIBC_UTILS_TESTING_THREAD_H
+
+namespace __llvm_libc {
+namespace testutils {
+
+class Thread {
+public:
+  typedef void FuncTypeNoArg();
+  typedef void FuncTypeOneArg(void *);
+
+  explicit Thread(FuncTypeNoArg &&F);
+  explicit Thread(FuncTypeOneArg &&F, void *Arg);
+
+  ~Thread();
+
+  void join();
+
+private:
+  void *StdThreadPtr;
+};
+
+} // namespace testutils
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_UTILS_TESTING_THREAD_H
diff --git a/libc/utils/testutils/Thread.cpp b/libc/utils/testutils/Thread.cpp
new file mode 100644
--- /dev/null
+++ b/libc/utils/testutils/Thread.cpp
@@ -0,0 +1,19 @@
+
+#include "Thread.h"
+
+#include <thread>
+
+namespace __llvm_libc {
+namespace testutils {
+
+Thread::Thread(FuncTypeNoArg &&F) : StdThreadPtr(new std::thread(F)) {}
+
+Thread::Thread(FuncTypeOneArg &&F, void *Arg)
+    : StdThreadPtr(new std::thread(F, Arg)) {}
+
+Thread::~Thread() { delete reinterpret_cast<std::thread *>(StdThreadPtr); }
+
+void Thread::join() { reinterpret_cast<std::thread *>(StdThreadPtr)->join(); }
+
+} // namespace testutils
+} // namespace __llvm_libc
diff --git a/libc/utils/testutils/abort.cpp b/libc/utils/testutils/abort.cpp
new file mode 100644
--- /dev/null
+++ b/libc/utils/testutils/abort.cpp
@@ -0,0 +1,10 @@
+
+#include <cstdlib>
+
+namespace __llvm_libc {
+namespace testutils {
+
+void abort() { std::abort(); }
+
+} // namespace testutils
+} // namespace __llvm_libc
diff --git a/libc/utils/testutils/linux/sleep.cpp b/libc/utils/testutils/linux/sleep.cpp
new file mode 100644
--- /dev/null
+++ b/libc/utils/testutils/linux/sleep.cpp
@@ -0,0 +1,10 @@
+
+#include <unistd.h>
+
+namespace __llvm_libc {
+namespace testutils {
+
+int sleep(unsigned int Seconds) { return ::sleep(Seconds); }
+
+} // namespace testutils
+} // namespace __llvm_libc