diff --git a/src/unix/kqueue.c b/src/unix/kqueue.c
index 58a6816d..cea58335 100644
--- a/src/unix/kqueue.c
+++ b/src/unix/kqueue.c
@@ -31,6 +31,7 @@
 #include <sys/sysctl.h>
 #include <sys/types.h>
 #include <sys/event.h>
+#include <unistd.h>
 #include <fcntl.h>
 #include <time.h>
 
diff --git a/src/unix/tcp.c b/src/unix/tcp.c
index ee94ab3e..c05dd5df 100644
--- a/src/unix/tcp.c
+++ b/src/unix/tcp.c
@@ -22,6 +22,7 @@
 #include "uv.h"
 #include "internal.h"
 
+#include <unistd.h>
 #include <assert.h>
 #include <errno.h>
 
diff --git a/src/unix/udp.c b/src/unix/udp.c
index 518c1ac5..10c2876e 100644
--- a/src/unix/udp.c
+++ b/src/unix/udp.c
@@ -26,6 +26,7 @@
 #include <string.h>
 #include <errno.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 
 static void uv__udp_run_completed(uv_udp_t* handle);