diff --git a/README.md b/README.md
index d05b9330..78ffb3f0 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,9 @@
 Install autoconf first for jemalloc
 
 ```
+git clone git@github.com:cloudwu/skynet.git
+git submodule update --init
+cd skynet
 make 'PLATFORM'  # PLATFORM can be linux, macosx, freebsd now
 ```
 
diff --git a/skynet-src/malloc_hook.c b/skynet-src/malloc_hook.c
index 424513c3..c0d91355 100644
--- a/skynet-src/malloc_hook.c
+++ b/skynet-src/malloc_hook.c
@@ -1,7 +1,6 @@
 #include <stdio.h>
 #include <string.h>
 #include <assert.h>
-//#include <malloc.h>
 
 #include "malloc_hook.h"
 
@@ -109,6 +108,8 @@ realloc(void *ptr, size_t size) {
     return fill_prefix(newptr);
 }
 
+#ifdef JEMALLOC_OVERRIDE_MEMALIGN
+
 void *
 memalign(size_t alignment, size_t size) {
     void *ptr = je_memalign(alignment, size+PREFIX_SIZE);
@@ -116,6 +117,8 @@ memalign(size_t alignment, size_t size) {
     return fill_prefix(ptr);
 }
 
+#endif
+
 void
 free(void *ptr) {
     if (ptr == NULL) return;