diff --git a/sb16_csp/cspctl.c b/sb16_csp/cspctl.c
index 95d4596..de0310a 100644
--- a/sb16_csp/cspctl.c
+++ b/sb16_csp/cspctl.c
@@ -28,6 +28,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/asoundlib.h>
+#include <linux/ioctl.h>
 
 /* --- commands --- */
 enum {