diff --git a/block/blk-merge.c b/block/blk-merge.c
index 3b0cd42..eafc94f 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -362,6 +362,18 @@
 		return 0;
 
 	/*
+	 * Don't merge file system requests and discard requests
+	 */
+	if ((req->cmd_flags & REQ_DISCARD) != (next->cmd_flags & REQ_DISCARD))
+		return 0;
+
+	/*
+	 * Don't merge discard requests and secure discard requests
+	 */
+	if ((req->cmd_flags & REQ_SECURE) != (next->cmd_flags & REQ_SECURE))
+		return 0;
+
+	/*
 	 * not contiguous
 	 */
 	if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))