diff --git a/src/newgrf_generic.cpp b/src/newgrf_generic.cpp
--- a/src/newgrf_generic.cpp
+++ b/src/newgrf_generic.cpp
@@ -42,7 +42,7 @@ struct GenericScopeResolver : public Sco
 	{
 	}
 
-	/* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
+	uint32 GetVariable(byte variable, uint32 parameter, bool *available) const override;
 
 private:
 	bool ai_callback; ///< Callback comes from the AI.
@@ -55,7 +55,7 @@ struct GenericResolverObject : public Re
 
 	GenericResolverObject(bool ai_callback, CallbackID callback = CBID_NO_CALLBACK);
 
-	/* virtual */ ScopeResolver *GetScope(VarSpriteGroupScope scope = VSG_SCOPE_SELF, byte relative = 0)
+	ScopeResolver *GetScope(VarSpriteGroupScope scope = VSG_SCOPE_SELF, byte relative = 0) override
 	{
 		switch (scope) {
 			case VSG_SCOPE_SELF: return &this->generic_scope;
@@ -63,7 +63,7 @@ struct GenericResolverObject : public Re
 		}
 	}
 
-	/* virtual */ const SpriteGroup *ResolveReal(const RealSpriteGroup *group) const;
+	const SpriteGroup *ResolveReal(const RealSpriteGroup *group) const override;
 };
 
 struct GenericCallback {