diff --git a/WHATS_NEW b/WHATS_NEW
index 6ae8126e3..002217d48 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.142 - 
 ====================================
+  Fix thinp watermark calc for data LV for faster dmeventd responce (2.02.133).
   Use use_blkid_wiping=0 if not defined in lvm.conf and support not compiled in.
   Do not check for suspended devices if scanning for lvmetad update.
   Fix part. table filter with external_device_info_source="udev" and blkid<2.20.
diff --git a/lib/thin/thin.c b/lib/thin/thin.c
index 9fbad32dc..c9ee9f530 100644
--- a/lib/thin/thin.c
+++ b/lib/thin/thin.c
@@ -295,9 +295,10 @@ static int _thin_pool_add_target_line(struct dev_manager *dm,
 	if (threshold < 50)
 		threshold = 50;
 	if (threshold < 100)
-		low_water_mark = (len * threshold + 99) / 100;
+		/* Translate to number of free pool blocks to trigger watermark */
+		low_water_mark = len / seg->chunk_size * (100 - threshold) / 100;
 	else
-		low_water_mark = len;
+		low_water_mark = 0;
 
 	if (!dm_tree_node_add_thin_pool_target(node, len,
 					       seg->transaction_id,