diff --git a/src/filter/filtermanager.cpp b/src/filter/filtermanager.cpp
index f9cb0af..f8bba08 100644
--- a/src/filter/filtermanager.cpp
+++ b/src/filter/filtermanager.cpp
@@ -231,6 +231,7 @@ void FilterManager::filter(const Akonadi::Item::List &messages, FilterManager::F
 {
     QList<qint64> itemIds;
 
+    itemIds.reserve(messages.size());
     foreach (const Akonadi::Item &item, messages) {
         itemIds << item.id();
     }
@@ -242,6 +243,7 @@ void FilterManager::filter(const Akonadi::Item::List &messages, SearchRule::Requ
 {
     QList<qint64> itemIds;
 
+    itemIds.reserve(messages.size());
     foreach (const Akonadi::Item &item, messages) {
         itemIds << item.id();
     }