diff --git a/lib/ecs/BUILD b/lib/ecs/BUILD
index 9864147..bda3255 100644
--- a/lib/ecs/BUILD
+++ b/lib/ecs/BUILD
@@ -2,6 +2,7 @@ load("@rules_rust//rust:rust.bzl", "rust_test", "rust_library")
 
 rust_library(
     name = "ecs",
+    edition = "2018",
     srcs = [
         "src/lib.rs",
 
diff --git a/lib/ecs/src/system.rs b/lib/ecs/src/system.rs
index 4aa2407..8623bfe 100644
--- a/lib/ecs/src/system.rs
+++ b/lib/ecs/src/system.rs
@@ -18,7 +18,7 @@ pub trait System<'a> {
 }
 
 trait WorldRunner<'a> {
-    fn run_world(&mut self, &'a  World);
+    fn run_world(&mut self, w: &'a World);
 }
 
 impl<'a, T> WorldRunner<'a> for T