diff --git a/sound/drivers/vx/vx_hwdep.c b/sound/drivers/vx/vx_hwdep.c
index 46df881..f7a6fbd 100644
--- a/sound/drivers/vx/vx_hwdep.c
+++ b/sound/drivers/vx/vx_hwdep.c
@@ -22,6 +22,7 @@
 
 #include <linux/device.h>
 #include <linux/firmware.h>
+#include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <sound/core.h>
 #include <sound/hwdep.h>