diff --git a/CMakeLists.txt b/CMakeLists.txt
index d38ca98..59c33c5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,8 +14,8 @@ include_directories("/usr/local/include")
 link_directories("/usr/local/lib")
 
 #在编译选项中加入c99支持
-add_compile_options(-std=c99)
-message(STATUS "optional:-std=c99")
+add_compile_options(-std=gnu99)
+message(STATUS "optional:-std=gnu99")
 
 add_executable(simple-dict-server server.c dict.c crypto.c)
 add_executable(simple-dict-client client.c crypto.c)