diff --git a/libc-top-half/musl/arch/wasm32/atomic_arch.h b/libc-top-half/musl/arch/wasm32/atomic_arch.h
index dd9428c9..c24ce2d7 100644
--- a/libc-top-half/musl/arch/wasm32/atomic_arch.h
+++ b/libc-top-half/musl/arch/wasm32/atomic_arch.h
@@ -1,4 +1,3 @@
-#define a_barrier() (__sync_synchronize())
 #define a_cas(p, t, s) (__sync_val_compare_and_swap((p), (t), (s)))
 #define a_crash() (__builtin_trap())
 #define a_clz_32 __builtin_clz