diff --git a/OpenRa.Game/Controller.cs b/OpenRa.Game/Controller.cs
index 4c7bfa9a56..4cd8089b36 100644
--- a/OpenRa.Game/Controller.cs
+++ b/OpenRa.Game/Controller.cs
@@ -41,6 +41,7 @@ namespace OpenRa.Game
                     dragEnd = GetWorldPos(mi);
 
             if (mi.Button == MouseButtons.Left && mi.Event == MouseInputEvent.Up)
+            {
                 if (dragStart.HasValue && !(dragStart.Value == GetWorldPos(mi)))
                 {
                     /* finalize drag selection */
@@ -50,6 +51,9 @@ namespace OpenRa.Game
                     /* finalize click selection */
                 }
 
+                dragStart = dragEnd = null;
+            }
+
             if (mi.Button == MouseButtons.None && mi.Event == MouseInputEvent.Move)
             {
                 /* update the cursor to reflect the thing under us - note this