diff --git a/lib/graphql/schema/input_object.rb b/lib/graphql/schema/input_object.rb
index 7dbd14dcaf..46c69c1826 100644
--- a/lib/graphql/schema/input_object.rb
+++ b/lib/graphql/schema/input_object.rb
@@ -145,7 +145,7 @@ def kind
         end
 
         # @api private
-        INVALID_OBJECT_MESSAGE = "Expected %{object} to be a key-value object responding to `to_h` or `to_unsafe_h`."
+        INVALID_OBJECT_MESSAGE = "Expected %{object} to be a key-value object."
 
         def validate_non_null_input(input, ctx, max_errors: nil)
           warden = ctx.warden