diff --git a/buffer/errmsg_cvt.c b/buffer/errmsg_cvt.c
index 4c5b269..e80ce1e 100644
--- a/buffer/errmsg_cvt.c
+++ b/buffer/errmsg_cvt.c
@@ -1,4 +1,5 @@
 #include <stdarg.h>
+#include <sys/types.h>
 #include <sys/uio.h>
 #include "errmsg.h"
 #include "str.h"
diff --git a/buffer/errmsg_warn.c b/buffer/errmsg_warn.c
index 305afd7..013c531 100644
--- a/buffer/errmsg_warn.c
+++ b/buffer/errmsg_warn.c
@@ -1,4 +1,5 @@
 #include <stdarg.h>
+#include <sys/types.h>
 #include <sys/uio.h>
 #include "errmsg.h"
 #include "str.h"
diff --git a/buffer/errmsg_warnsys.c b/buffer/errmsg_warnsys.c
index bd11ae7..763fd99 100644
--- a/buffer/errmsg_warnsys.c
+++ b/buffer/errmsg_warnsys.c
@@ -1,4 +1,5 @@
 #include <stdarg.h>
+#include <sys/types.h>
 #include <sys/uio.h>
 #include "errmsg.h"
 #include "str.h"