diff --git a/src/search/widgethandler/tagrulewidgethandler.cpp b/src/search/widgethandler/tagrulewidgethandler.cpp
index a6071ae..bb8c549 100644
--- a/src/search/widgethandler/tagrulewidgethandler.cpp
+++ b/src/search/widgethandler/tagrulewidgethandler.cpp
@@ -88,7 +88,7 @@ void FillTagComboJob::onTagsFetched(KJob *job)
     const auto lst = fetchJob->tags();
     for (const Akonadi::Tag &tag : lst) {
         QString iconName = QStringLiteral("mail-tagged");
-        Akonadi::TagAttribute *attr = tag.attribute<Akonadi::TagAttribute>();
+        const Akonadi::TagAttribute *attr = tag.attribute<Akonadi::TagAttribute>();
         if (attr) {
             if (!attr->iconName().isEmpty()) {
                 iconName = attr->iconName();
diff --git a/src/tag/tag.cpp b/src/tag/tag.cpp
index 9ae6147..084d1ca 100644
--- a/src/tag/tag.cpp
+++ b/src/tag/tag.cpp
@@ -50,7 +50,7 @@ Tag::Ptr Tag::fromAkonadi(const Akonadi::Tag &akonadiTag)
     tag->iconName = QStringLiteral("mail-tagged");
     tag->inToolbar = false;
     tag->isImmutable = akonadiTag.isImmutable();
-    Akonadi::TagAttribute *attr = akonadiTag.attribute<Akonadi::TagAttribute>();
+    const Akonadi::TagAttribute *attr = akonadiTag.attribute<Akonadi::TagAttribute>();
     if (attr) {
         if (!attr->iconName().isEmpty()) {
             tag->iconName = attr->iconName();
diff --git a/src/util/mailutil.cpp b/src/util/mailutil.cpp
index e76ce2a..be17226 100644
--- a/src/util/mailutil.cpp
+++ b/src/util/mailutil.cpp
@@ -280,9 +280,10 @@ QStringList MailCommon::Util::foundMailer()
 
 MailCommon::ExpireCollectionAttribute *MailCommon::Util::expirationCollectionAttribute(const Akonadi::Collection &collection, bool &mustDeleteExpirationAttribute)
 {
+    Akonadi::Collection mutableCollection = collection;
     MailCommon::ExpireCollectionAttribute *attr = nullptr;
-    if (collection.hasAttribute<MailCommon::ExpireCollectionAttribute>()) {
-        attr = collection.attribute<MailCommon::ExpireCollectionAttribute>();
+    if (mutableCollection.hasAttribute<MailCommon::ExpireCollectionAttribute>()) {
+        attr = mutableCollection.attribute<MailCommon::ExpireCollectionAttribute>();
         mustDeleteExpirationAttribute = false;
     } else {
         attr = new MailCommon::ExpireCollectionAttribute();