diff --git a/src/win_generic.c b/src/win_generic.c
index dc45b02..29cc6a5 100644
--- a/src/win_generic.c
+++ b/src/win_generic.c
@@ -329,6 +329,9 @@ win_event_handler(HWND hwnd, UINT umsg, WPARAM wParam, LPARAM lParam)
 		}
 		DragFinish((HDROP)wParam);
 		break;
+	case WM_KILLFOCUS:
+		adb_all_keys_up(); // ALT-TAB doesn't send key-up messages
+		break;
 	}
 	switch(umsg) {
 		HANDLE_MSG(hwnd, WM_KEYUP, WIN_EVENT_KEY);