diff --git a/src/OpenThreads/common/Atomic.cpp b/src/OpenThreads/common/Atomic.cpp
index a2788257a..21c336435 100644
--- a/src/OpenThreads/common/Atomic.cpp
+++ b/src/OpenThreads/common/Atomic.cpp
@@ -143,7 +143,7 @@ bool
 AtomicPtr::assign(void* ptrNew, const void* const ptrOld)
 {
 #if defined(_OPENTHREADS_ATOMIC_USE_GCC_BUILTINS)
-    return __sync_bool_compare_and_swap(&_ptr, ptrOld, ptrNew);
+    return __sync_bool_compare_and_swap(&_ptr, (void*)ptrOld, ptrNew);
 #elif defined(_OPENTHREADS_ATOMIC_USE_WIN32_INTERLOCKED)
     return ptrOld == InterlockedCompareExchangePointer((PVOID volatile*)&_ptr, (PVOID)ptrNew, (PVOID)ptrOld);
 #elif defined(_OPENTHREADS_ATOMIC_USE_BSD_ATOMIC)