diff --git a/include/Makefile.am b/include/Makefile.am
index 3814fce..a552026 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -1,7 +1,6 @@
 noinst_HEADERS =
-noinst_HEADERS += signal.h
-noinst_HEADERS += unistd.h
 noinst_HEADERS += machine/endian.h
+noinst_HEADERS += sys/cdefs.h
 noinst_HEADERS += sys/queue.h
 noinst_HEADERS += sys/socket.h
 noinst_HEADERS += sys/types.h
@@ -11,14 +10,16 @@ noinst_HEADERS += sys/wait.h
 noinst_HEADERS += err.h
 noinst_HEADERS += ifaddrs.h
 noinst_HEADERS += imsg.h
-noinst_HEADERS += string.h
 noinst_HEADERS += md5.h
 noinst_HEADERS += sha2.h
+noinst_HEADERS += signal.h
 noinst_HEADERS += sha2_openbsd.h
-noinst_HEADERS += stdlib.h
 noinst_HEADERS += Makefile.in
 noinst_HEADERS += paths.h
 noinst_HEADERS += poll.h
 noinst_HEADERS += stdio.h
+noinst_HEADERS += stdlib.h
+noinst_HEADERS += string.h
 noinst_HEADERS += time.h
 noinst_HEADERS += tls.h
+noinst_HEADERS += unistd.h