diff --git a/Cargo.toml b/Cargo.toml
index 9eff9a3..eed8ce7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,3 +22,5 @@ members = [
     "examples/no_macro/history",
     "examples/no_macro/calculator",
 ]
+
+resolver = "2"