diff --git a/CMakeLists.txt b/CMakeLists.txt
index cb68033..ba5d257 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,6 +36,9 @@ include(ECMQmlModule)
 ## Disable use of C++ API deprecated in Qt 5.15
 add_compile_definitions(QT_DISABLE_DEPRECATED_UP_TO=0x050F00)
 
+## Enable -Werror by default:
+add_compile_options(-Werror)
+
 ## Shared macros and functions:
 if(NOT LIRI_LOCAL_ECM)
     find_package(LiriCMakeShared "2.0.99" REQUIRED NO_MODULE)
diff --git a/src/manager/session.cpp b/src/manager/session.cpp
index 2199630..2189cbd 100644
--- a/src/manager/session.cpp
+++ b/src/manager/session.cpp
@@ -279,7 +279,7 @@ void Session::shutdown()
 
     // Stop modules
     std::reverse(m_loadedModules.begin(), m_loadedModules.end());
-    for (auto module : qAsConst(m_loadedModules)) {
+    for (auto module : std::as_const(m_loadedModules)) {
         auto instance = dynamic_cast<QObject *>(module);
         const auto name = m_pluginRegistry->getNameForInstance(instance);