diff --git a/tests/processed_unittest.cpp b/tests/processed_unittest.cpp
index ab963cb..8f20344 100644
--- a/tests/processed_unittest.cpp
+++ b/tests/processed_unittest.cpp
@@ -1605,6 +1605,7 @@ BOOST_AUTO_TEST_CASE(zero_phrase_acts_are_handled)
 BOOST_AUTO_TEST_CASE(average_multiplier_rounds_down)
 {
     std::vector<Note> notes;
+    notes.reserve(11);
     for (auto i = 0; i < 11; ++i) {
         notes.push_back(make_note(i));
     }