diff --git a/include/mimalloc/atomic.h b/include/mimalloc/atomic.h
index 6fb4951c..1951b470 100644
--- a/include/mimalloc/atomic.h
+++ b/include/mimalloc/atomic.h
@@ -303,7 +303,7 @@ static inline void mi_atomic_yield(void) {
 }
 #elif (defined(__GNUC__) || defined(__clang__)) && \
       (defined(__x86_64__) || defined(__i386__) || defined(__arm__) || defined(__armel__) || defined(__ARMEL__) || \
-       defined(__aarch64__) || defined(__powerpc__) || defined(__ppc__) || defined(__PPC__))
+       defined(__aarch64__) || defined(__powerpc__) || defined(__ppc__) || defined(__PPC__)) || defined(__POWERPC__)
 #if defined(__x86_64__) || defined(__i386__)
 static inline void mi_atomic_yield(void) {
   __asm__ volatile ("pause" ::: "memory");
@@ -316,10 +316,16 @@ static inline void mi_atomic_yield(void) {
 static inline void mi_atomic_yield(void) {
   __asm__ volatile("yield" ::: "memory");
 }
-#elif defined(__powerpc__) || defined(__ppc__) || defined(__PPC__)
+#elif defined(__powerpc__) || defined(__ppc__) || defined(__PPC__) || defined(__POWERPC__)
+#ifdef __APPLE__
+static inline void mi_atomic_yield(void) {
+  __asm__ volatile ("or r27,r27,r27" ::: "memory");
+}
+#else
 static inline void mi_atomic_yield(void) {
   __asm__ __volatile__ ("or 27,27,27" ::: "memory");
 }
+#endif
 #elif defined(__armel__) || defined(__ARMEL__)
 static inline void mi_atomic_yield(void) {
   __asm__ volatile ("nop" ::: "memory");