diff --git a/action.yml b/action.yml
index 8e39ac9..f0701f2 100644
--- a/action.yml
+++ b/action.yml
@@ -7,6 +7,7 @@ inputs:
 # Deprecated option, do not use. Will not be supported after October 1, 2019
   version:
     description: 'Deprecated. Use dotnet-version instead. Will not be supported after October 1, 2019'
+    deprecationMessage: 'The version property will not be supported after October 1, 2019. Use dotnet-version instead'
 runs:
   using: 'node12'
   main: 'lib/setup-dotnet.js'