diff --git a/src/driver.h b/src/driver.h
index ec4abf3e4e..24636a43a2 100644
--- a/src/driver.h
+++ b/src/driver.h
@@ -8,6 +8,7 @@
 
 # include "config.h"
 
+# include <unistd.h>
 # include <libxml/uri.h>
 
 # include "internal.h"