diff --git a/CMakeLists.txt b/CMakeLists.txt
index 70582fb..9274119 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,6 +8,8 @@ set(VERSION 0.1.0)
 option(DEBUG     "compile with debug symbol"    OFF)
 option(BUNDLE_CIVETWEB     "bundle civetweb with uts-server"    OFF)
 
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99 -D_BSD_SOURCE -D_XOPEN_SOURCE=700")
+
 if(DEBUG)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0 -g")
     set(CMAKE_BUILD_TYPE Debug)
@@ -19,7 +21,7 @@ add_custom_target(tag
     git push origin ${VERSION}
 )
 
-set(CMAKE_C_FLAGS "${CMAKE_CXX_FLAGS} -DUTS_VERSION='\"${VERSION}\"'")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DUTS_VERSION='\"${VERSION}\"'")
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake/")
 
diff --git a/src/cmd/uts-server.c b/src/cmd/uts-server.c
index bfa7d2d..9205193 100644
--- a/src/cmd/uts-server.c
+++ b/src/cmd/uts-server.c
@@ -7,6 +7,8 @@
 #include <argp.h>
 #include <sys/syslog.h>
 #include <libgen.h>
+#include <limits.h>
+#include <linux/limits.h>
 #include "http.h"
 
 const char *argp_program_version = UTS_VERSION;