diff --git a/README.md b/README.md
index 293a33410f5e46ac25316b0c897b0412cd18d8b2..d34cb4f2b8483eab7e8b9e562d44fa65449ee2e3 100644
--- a/README.md
+++ b/README.md
@@ -58,3 +58,6 @@ only supports grub. This only matters if you're using `shared-bootdir-helper-mul
 
 depends on: sed, bash, 
 
+## WARNING
+
+DO NOT upgrade cryptsetup to 2.7.0. It will force using new hash function, and break your existing dm-crypt setup.