diff --git a/block-raw-posix.c b/block-raw-posix.c
index af3d468750..49dd528d26 100644
--- a/block-raw-posix.c
+++ b/block-raw-posix.c
@@ -75,7 +75,11 @@
 
 /* OS X does not have O_DSYNC */
 #ifndef O_DSYNC
+#ifdef O_SYNC
 #define O_DSYNC O_SYNC
+#elif defined(O_FSYNC)
+#define O_DSYNC O_FSYNC
+#endif
 #endif
 
 /* Approximate O_DIRECT with O_DSYNC if O_DIRECT isn't available */