diff --git a/thermion_dart/lib/src/viewer/src/thermion_viewer_base.dart b/thermion_dart/lib/src/viewer/src/thermion_viewer_base.dart
index 0c8c5760..47c70c3f 100644
--- a/thermion_dart/lib/src/viewer/src/thermion_viewer_base.dart
+++ b/thermion_dart/lib/src/viewer/src/thermion_viewer_base.dart
@@ -71,6 +71,12 @@ abstract class ThermionViewer {
   ///
   Future<SwapChain> createSwapChain(int handle);
 
+  ///
+  ///
+  ///
+  Future destroySwapChain(
+      covariant SwapChain swapChain);
+
   ///
   ///
   ///
@@ -80,7 +86,13 @@ abstract class ThermionViewer {
   ///
   ///
   ///
-  Future setRenderTarget(covariant RenderTarget renderTarget);
+  Future destroyRenderTarget(
+      covariant RenderTarget renderTarget);
+
+  ///
+  ///
+  ///
+  Future setRenderTarget(covariant RenderTarget? renderTarget);
 
   ///
   ///