diff --git a/scsh/sleep1.c b/scsh/sleep1.c
index b3cdf0e..0d735b4 100644
--- a/scsh/sleep1.c
+++ b/scsh/sleep1.c
@@ -1,5 +1,13 @@
+#include "sysdep.h"
+
 #include <sys/types.h>
 #include <sys/time.h>
+#if defined(HAVE_SELECT)
+#  include <sys/types.h>	/* for FD_SET and friends (BSD) */
+#if defined(HAVE_SYS_SELECT_H)
+#  include <sys/select.h>
+#endif
+#endif
 #include <unistd.h>
 #include <time.h>
 #include "../scheme48.h"