diff --git a/core/src/consensus.rs b/core/src/consensus.rs
index 96929b899e..8c2965faf7 100644
--- a/core/src/consensus.rs
+++ b/core/src/consensus.rs
@@ -451,7 +451,7 @@ impl Tower {
         self.stray_restored_slot
     }
 
-    pub fn last_vote(&mut self) -> Vote {
+    pub fn last_vote(&self) -> Vote {
         self.last_vote.clone()
     }