diff --git a/libvips/foreign/dzsave.c b/libvips/foreign/dzsave.c
index e9e1137f..61821120 100644
--- a/libvips/foreign/dzsave.c
+++ b/libvips/foreign/dzsave.c
@@ -176,6 +176,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 
 #include <vips/vips.h>
 #include <vips/internal.h>