diff --git a/src/driver.h b/src/driver.h
index ec4abf3e4e3730459a405946c5c62fc9687156ff..24636a43a21fba210a6aeede2f0c7f80e0706031 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"