diff --git a/package.yaml b/package.yaml
index 687f783d5b080e5d10670c52340cc7877cb2cf4a..a6911b827f5b5aa9c86038c9bfd000fa80b1bc7a 100644
--- a/package.yaml
+++ b/package.yaml
@@ -55,6 +55,7 @@ ghc-options:
 - -fwarn-tabs
 - -Wall
 - -Werror
+- -Wwarn=deprecations
 - -O2
 
 library: