diff --git a/unit-tests/btree_damage_visitor_t.cc b/unit-tests/btree_damage_visitor_t.cc
index 3b6c2f0..7e446d5 100644
--- a/unit-tests/btree_damage_visitor_t.cc
+++ b/unit-tests/btree_damage_visitor_t.cc
@@ -448,7 +448,7 @@ namespace {
  			}
  		}
 
-		void expect_damage(btree_path path, base::run<uint64_t> keys) {
+		void expect_damage(btree_path const &path, base::run<uint64_t> const &keys) {
 			EXPECT_CALL(damage_visitor_, visit(Eq(path), DamagedKeys(keys))).Times(1);
 		}