diff --git a/src/opt.c b/src/opt.c
index 6b51d855..9d4323df 100644
--- a/src/opt.c
+++ b/src/opt.c
@@ -40,6 +40,7 @@
 #include "expr.h"
 #include "list.h"
 #include "pwcache.h"
+#include "xspawn.h"
 
 #include <errno.h>
 #include <limits.h>