diff --git a/crates/bevy_ecs/Cargo.toml b/crates/bevy_ecs/Cargo.toml
index be4dea2ddc93d7..e83a7b24970880 100644
--- a/crates/bevy_ecs/Cargo.toml
+++ b/crates/bevy_ecs/Cargo.toml
@@ -31,6 +31,9 @@ downcast-rs = "1.2"
 rand = "0.8"
 serde = "1"
 
+[dev-dependencies]
+parking_lot = "0.11"
+
 [[example]]
 name = "events"
 path = "examples/events.rs"