diff --git a/cumulus/pallets/collator-selection/src/lib.rs b/cumulus/pallets/collator-selection/src/lib.rs
index 17dc1a552c2de..9d7e62af3c68f 100644
--- a/cumulus/pallets/collator-selection/src/lib.rs
+++ b/cumulus/pallets/collator-selection/src/lib.rs
@@ -972,7 +972,7 @@ pub mod pallet {
 			let result = Self::assemble_collators();
 
 			frame_system::Pallet::<T>::register_extra_weight_unchecked(
-				T::WeightInfo::new_session(candidates_len_before, removed),
+				T::WeightInfo::new_session(removed, candidates_len_before),
 				DispatchClass::Mandatory,
 			);
 			Some(result)
diff --git a/prdoc/pr_5430.prdoc b/prdoc/pr_5430.prdoc
new file mode 100644
index 0000000000000..83d6d81e252e2
--- /dev/null
+++ b/prdoc/pr_5430.prdoc
@@ -0,0 +1,13 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: "pallet-collator-selection: correctly register weight in `new_session`"
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      - Fixes an incorrect usage of the `WeightInfo` trait for `new_session`.
+
+crates:
+  - name: pallet-collator-selection
+    bump: patch