diff --git a/README.md b/README.md
index d5c9386d..a282a167 100644
--- a/README.md
+++ b/README.md
@@ -252,7 +252,8 @@ Usage
                                   only available in server mode
 
        [--fast-open]              enable TCP fast open,
-                                  only available on Linux kernel > 3.7.0
+                                  only available in local and server mode,
+                                  with Linux kernel > 3.7.0
 
        [--acl <acl_file>]         config file of ACL (Access Control List)
                                   only available in local and server mode
diff --git a/src/utils.c b/src/utils.c
index 12f9a5e3..2398381a 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -255,7 +255,9 @@ void usage()
     printf(
         "       [--fast-open]              enable TCP fast open,\n");
     printf(
-        "                                  only available on Linux kernel > 3.7.0\n");
+        "                                  only available in local and server mode,\n");
+    printf(
+        "                                  with Linux kernel > 3.7.0\n");
     printf("\n");
     printf(
         "       [--acl <acl_file>]         config file of ACL (Access Control List)\n");