diff --git a/substrate/core/sr-io/without_std.rs b/substrate/core/sr-io/without_std.rs
index e4e32bd17d..08b1a3c70a 100644
--- a/substrate/core/sr-io/without_std.rs
+++ b/substrate/core/sr-io/without_std.rs
@@ -367,7 +367,7 @@ pub fn set_storage(key: &[u8], value: &[u8]) {
 pub fn set_child_storage(storage_key: &[u8], key: &[u8], value: &[u8]) {
 	unsafe {
 		ext_set_child_storage.get()(
-			storage_key.as_ptr(), key.len() as u32,
+			storage_key.as_ptr(), storage_key.len() as u32,
 			key.as_ptr(), key.len() as u32,
 			value.as_ptr(), value.len() as u32
 		);
diff --git a/substrate/core/state-machine/src/ext.rs b/substrate/core/state-machine/src/ext.rs
index 63a5c39fef..a9411f26ad 100644
--- a/substrate/core/state-machine/src/ext.rs
+++ b/substrate/core/state-machine/src/ext.rs
@@ -297,7 +297,8 @@ where
 		}
 
 		let mut transaction = B::Transaction::default();
-		let child_storage_keys: Vec<_> = self.overlay.prospective.children.keys().cloned().collect();
+		let child_storage_keys: std::collections::BTreeSet<_> = self.overlay.prospective.children.keys().cloned()
+			.chain(self.overlay.committed.children.keys().cloned()).collect();
 
 		for key in child_storage_keys {
 			let (_, t) = self.child_storage_root_transaction(&key);