3 files changed, 10 insertions, 2 deletions
diff --git a/backends/timer/default/default-timer.h b/backends/timer/default/default-timer.h
index e7ac3d122f..778c69b32d 100644
--- a/backends/timer/default/default-timer.h
+++ b/backends/timer/default/default-timer.h
@@ -40,7 +40,8 @@ private:
 
 public:
 	DefaultTimerManager();
-	~DefaultTimerManager();
+	virtual ~DefaultTimerManager();
+
 	bool installTimerProc(TimerProc proc, int32 interval, void *refCon);
 	void removeTimerProc(TimerProc proc);
 
diff --git a/backends/timer/sdl/sdl-timer.cpp b/backends/timer/sdl/sdl-timer.cpp
index 0fbe12589e..94932d61ba 100644
--- a/backends/timer/sdl/sdl-timer.cpp
+++ b/backends/timer/sdl/sdl-timer.cpp
@@ -34,14 +34,17 @@ static Uint32 timer_handler(Uint32 interval, void *param) {
 }
 
 SdlTimerManager::SdlTimerManager() {
+	// Initializes the SDL timer subsystem
 	if (SDL_InitSubSystem(SDL_INIT_TIMER) == -1) {
 		error("Could not initialize SDL: %s", SDL_GetError());
 	}
 
+	// Creates the timer callback
 	_timerID = SDL_AddTimer(10, &timer_handler, this);
 }
 
 SdlTimerManager::~SdlTimerManager() {
+	// Removes the timer callback
 	SDL_RemoveTimer(_timerID);
 }
 
diff --git a/backends/timer/sdl/sdl-timer.h b/backends/timer/sdl/sdl-timer.h
index 19629151ca..5995aed4b0 100644
--- a/backends/timer/sdl/sdl-timer.h
+++ b/backends/timer/sdl/sdl-timer.h
@@ -34,10 +34,14 @@
 #include <SDL.h>
 #endif
 
+/**
+ * SDL timer manager. Setups the timer callback for
+ * DefaultTimerManager.
+ */
 class SdlTimerManager : public DefaultTimerManager {
 public:
 	SdlTimerManager();
-	~SdlTimerManager();
+	virtual ~SdlTimerManager();
 
 protected:
 	SDL_TimerID _timerID;