diff --git a/include/nuttx/mm/mm.h b/include/nuttx/mm/mm.h
index 6d40ae11eb..854c54f34c 100644
--- a/include/nuttx/mm/mm.h
+++ b/include/nuttx/mm/mm.h
@@ -157,7 +157,7 @@
 #endif
 
 #if CONFIG_MM_DEFAULT_ALIGNMENT == 0
-#  define MM_ALIGN       (2 * sizeof(uintptr_t))
+#  define MM_ALIGN       sizeof(uintptr_t)
 #else
 #  define MM_ALIGN       CONFIG_MM_DEFAULT_ALIGNMENT
 #endif
diff --git a/mm/Kconfig b/mm/Kconfig
index 6d77d27e3e..356daa2196 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -62,7 +62,7 @@ config MM_KERNEL_HEAPSIZE
 
 config MM_DEFAULT_ALIGNMENT
 	int "Memory default alignment in bytes"
-	default 0
+	default 8
 	range 0 64
 	---help---
 		The memory default alignment in bytes, if this value is 0, the real