diff --git a/tests/picture_loader_benchmark/settings_cache_mock.cpp b/tests/picture_loader_benchmark/settings_cache_mock.cpp
index 13e831b62..70b08644c 100644
--- a/tests/picture_loader_benchmark/settings_cache_mock.cpp
+++ b/tests/picture_loader_benchmark/settings_cache_mock.cpp
@@ -144,6 +144,10 @@ SettingsCache::SettingsCache()
     loadPaths();
 }
 
+// The real destructor deletes the release channels; this mock never creates any,
+// but the vtable still needs the definition.
+SettingsCache::~SettingsCache() = default;
+
 void SettingsCache::loadPaths()
 {
     QString dataPath = getDataPath();