diff --git a/src/extension.h b/src/extension.h
index 702b6730..83cb6633 100644
--- a/src/extension.h
+++ b/src/extension.h
@@ -137,11 +137,16 @@ class QDLLEXPORT IExtension
   //
   const auto& requirements() const { return m_Requirements; }
 
+public:
   virtual ~IExtension() {}
+  IExtension& operator=(const IExtension&) = delete;
 
 protected:
   IExtension(std::filesystem::path path, ExtensionMetaData metadata);
 
+public:
+  IExtension(const IExtension&) = default;
+
 private:
   std::filesystem::path m_Path;
   ExtensionMetaData m_MetaData;
diff --git a/src/requirements.cpp b/src/requirements.cpp
index f911a149..08c0e77c 100644
--- a/src/requirements.cpp
+++ b/src/requirements.cpp
@@ -23,7 +23,7 @@ ExtensionRequirement::ExtensionRequirement(
 
 ExtensionRequirement::~ExtensionRequirement() = default;
 
-bool ExtensionRequirement::check(IOrganizer* organizer) const
+bool ExtensionRequirement::check([[maybe_unused]] IOrganizer* organizer) const
 {
   return true;
 }
@@ -45,6 +45,7 @@ ExtensionRequirementFactory::parseRequirements(const ExtensionMetaData& metadata
 
   std::vector<ExtensionRequirement> requirements;
   for (const auto& json_requirement : json_requirements.toArray()) {
+    // TODO
   }
 
   return requirements;