diff --git a/libcxxabi/src/cxa_guard_impl.h b/libcxxabi/src/cxa_guard_impl.h
--- a/libcxxabi/src/cxa_guard_impl.h
+++ b/libcxxabi/src/cxa_guard_impl.h
@@ -220,10 +220,10 @@
 //                     Global Mutex Implementation
 //===----------------------------------------------------------------------===//
 
+#ifndef _LIBCXXABI_HAS_NO_THREADS
 struct LibcppMutex;
 struct LibcppCondVar;
 
-#ifndef _LIBCXXABI_HAS_NO_THREADS
 struct LibcppMutex {
   LibcppMutex() = default;
   LibcppMutex(LibcppMutex const&) = delete;
@@ -514,6 +514,7 @@
   using type = InitByteNoThreads;
 };
 
+#ifndef _LIBCXXABI_HAS_NO_THREADS
 template <>
 struct SelectImplementation<Implementation::GlobalLock> {
   using type = InitByteGlobalMutex<
@@ -526,6 +527,7 @@
   using type =
       InitByteFutex<PlatformFutexWait, PlatformFutexWake, PlatformThreadID>;
 };
+#endif
 
 // TODO(EricWF): We should prefer the futex implementation when available. But
 // it should be done in a separate step from adding the implementation.
@@ -535,7 +537,7 @@
 #elif defined(_LIBCXXABI_USE_FUTEX)
     Implementation::Futex;
 #else
-   Implementation::GlobalLock;
+    Implementation::GlobalLock;
 #endif
 
 static_assert(CurrentImplementation != Implementation::Futex