diff --git a/Mamesaver/Power/PowerManager.cs b/Mamesaver/Power/PowerManager.cs
index 374e48b..bc62715 100644
--- a/Mamesaver/Power/PowerManager.cs
+++ b/Mamesaver/Power/PowerManager.cs
@@ -76,7 +76,7 @@ public void Initialise()
                 powerType.Value.ToString(), _sleepTimeout.TotalMinutes);
 
             // Create a timer which fires once when the display or computer should go to sleep
-            _sleepTimer = new Timer { Interval = (int)_sleepTimeout.TotalMilliseconds, AutoReset = false };
+            _sleepTimer = new Timer { Interval = Math.Min(_sleepTimeout.TotalMilliseconds, int.MaxValue), AutoReset = false };
 
             _sleepTimer.Elapsed += SleepTimerTick;
             _sleepTimer.Start();
@@ -125,7 +125,7 @@ private void PowerStateChanged(object sender, EventArgs args)
                 powerType.Value.ToString(), _sleepTimeout.TotalMinutes);
 
             // Update sleep timer on power state change due to different sleep configurations
-            _sleepTimer.Interval = (int)_sleepTimeout.TotalMilliseconds;
+            _sleepTimer.Interval = Math.Min(_sleepTimeout.TotalMilliseconds, int.MaxValue);
 
             _sleepTimer.Stop();
             _sleepTimer.Start();
diff --git a/Mamesaver/Windows/UserActivityHook.cs b/Mamesaver/Windows/UserActivityHook.cs
index dda76f1..233b6b7 100644
--- a/Mamesaver/Windows/UserActivityHook.cs
+++ b/Mamesaver/Windows/UserActivityHook.cs
@@ -479,20 +479,21 @@ public UserActivityHook(bool InstallMouseHook, bool InstallKeyboardHook)
             Start(InstallMouseHook, InstallKeyboardHook);
         }
 
-        public void Dispose()
+        protected virtual void Dispose(bool disposing)
         {
-            //uninstall hooks and do not throw exceptions
-            Stop(true, true, false); 
+            if (disposing)
+            {
+                Stop(true, true, false);
+            }
         }
-
-        /// <summary>
-        /// Destruction.
-        /// </summary>
-        ~UserActivityHook()
+        public void Dispose()
         {
-            Dispose();
+            Dispose(true);
+            GC.SuppressFinalize(this);
         }
 
+        ~UserActivityHook() => Dispose(false);
+
         /// <summary>
         /// Occurs when the user moves the mouse, presses any mouse button or scrolls the wheel
         /// </summary>