diff --git a/compat/atomics/suncc/stdatomic.h b/compat/atomics/suncc/stdatomic.h
index 4a864a4ae9..0cf89e0f78 100644
--- a/compat/atomics/suncc/stdatomic.h
+++ b/compat/atomics/suncc/stdatomic.h
@@ -108,7 +108,7 @@ static inline int atomic_compare_exchange_strong(intptr_t *object, intptr_t *exp
                                                  intptr_t desired)
 {
     intptr_t  old = *expected;
-    *expected = atomic_cas_ptr(object, old, desired);
+    *expected = (intptr_t)atomic_cas_ptr(object, (void *)old, (void *)desired);
     return *expected == old;
 }
 
diff --git a/compat/atomics/win32/stdatomic.h b/compat/atomics/win32/stdatomic.h
index 092f453978..bb8e6e7e15 100644
--- a/compat/atomics/win32/stdatomic.h
+++ b/compat/atomics/win32/stdatomic.h
@@ -105,7 +105,8 @@ static inline int atomic_compare_exchange_strong(intptr_t *object, intptr_t *exp
                                                  intptr_t desired)
 {
     intptr_t old = *expected;
-    *expected = InterlockedCompareExchangePointer(object, desired, old);
+    *expected = (intptr_t)InterlockedCompareExchangePointer(
+        (PVOID *)object, (PVOID)desired, (PVOID)old);
     return *expected == old;
 }