diff --git a/include/linux/fs.h b/include/linux/fs.h
index 79cea80..891f7d6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -304,6 +304,7 @@
 #define BLKIOOPT _IO(0x12,121)
 #define BLKALIGNOFF _IO(0x12,122)
 #define BLKPBSZGET _IO(0x12,123)
+#define BLKDISCARDZEROES _IO(0x12,124)
 
 #define BMAP_IOCTL 1		/* obsolete - kept for compatibility */
 #define FIBMAP	   _IO(0x00,1)	/* bmap access */