diff --git a/CMakeLists.txt b/CMakeLists.txt
index afad8123..09f37d6d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 2.8.5)
 project(sway C)
 set(CMAKE_C_FLAGS "-g")
 set(CMAKE_C_STANDARD 99)
+SET(CMAKE_C_EXTENSIONS OFF)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "bin/")
 add_definitions("-Wall -Wextra -Wno-unused-parameter")
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${PROJECT_SOURCE_DIR}/CMake)
diff --git a/sway/commands.c b/sway/commands.c
index e79746ae..71eb9d70 100644
--- a/sway/commands.c
+++ b/sway/commands.c
@@ -7,6 +7,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <ctype.h>
+#include <sys/types.h>
 #include "stringop.h"
 #include "layout.h"
 #include "focus.h"
diff --git a/sway/main.c b/sway/main.c
index e03588ea..97243f99 100644
--- a/sway/main.c
+++ b/sway/main.c
@@ -3,6 +3,7 @@
 #include <stdbool.h>
 #include <wlc/wlc.h>
 #include <sys/wait.h>
+#include <sys/types.h>
 #include <signal.h>
 #include <getopt.h>
 #include "layout.h"