diff --git a/README.md b/README.md
index 011c0e6..245174a 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@
 This is a small library for managing global player state, so that changes made
 from different mods do not result in unexpected behavior. The README gives an
 introduction to the mod, but you might want to reference API.md along the way.
+This mod, combined with playereffects, deprecates monoidal_effects.
 
 Global Player State
 ===================