diff --git a/src/blockstore.h b/src/blockstore.h
index 46930543..01810c2b 100644
--- a/src/blockstore.h
+++ b/src/blockstore.h
@@ -21,7 +21,7 @@
 // Memory alignment for direct I/O (usually 512 bytes)
 // All other alignments must be a multiple of this one
 #ifndef MEM_ALIGNMENT
-#define MEM_ALIGNMENT 512
+#define MEM_ALIGNMENT 4096
 #endif
 
 // Default block size is 128 KB, current allowed range is 4K - 128M
diff --git a/src/osd_rmw.h b/src/osd_rmw.h
index 0e175d4f..ecfa4770 100644
--- a/src/osd_rmw.h
+++ b/src/osd_rmw.h
@@ -8,7 +8,7 @@
 #include "osd_id.h"
 
 #ifndef MEM_ALIGNMENT
-#define MEM_ALIGNMENT 512
+#define MEM_ALIGNMENT 4096
 #endif
 
 struct buf_len_t