diff --git a/rs/interfaces/state_manager/mocks/src/lib.rs b/rs/interfaces/state_manager/mocks/src/lib.rs
index 7d0d55e7cbe7..e6a6fe48f074 100644
--- a/rs/interfaces/state_manager/mocks/src/lib.rs
+++ b/rs/interfaces/state_manager/mocks/src/lib.rs
@@ -1,6 +1,6 @@
 use ic_crypto_tree_hash::{LabeledTree, MixedHashTree};
 use ic_interfaces_state_manager::{
-    CertificationMask, CertificationScope, CertifiedStateSnapshot, Labeled, StateHashError,
+    CertificationScope, CertifiedStateSnapshot, Labeled, StateHashError,
     StateManager, StateManagerResult, StateReader,
 };
 use ic_replicated_state::ReplicatedState;