diff --git a/scene/2d/camera_2d.cpp b/scene/2d/camera_2d.cpp
index 8195d98f55..a6362ab0d5 100644
--- a/scene/2d/camera_2d.cpp
+++ b/scene/2d/camera_2d.cpp
@@ -232,6 +232,7 @@ void Camera2D::_notification(int p_what) {
 
 		} break;
 		case NOTIFICATION_ENTER_TREE: {
+			ERR_FAIL_COND(!is_inside_tree());
 			if (custom_viewport && ObjectDB::get_instance(custom_viewport_id)) {
 				viewport = custom_viewport;
 			} else {
diff --git a/scene/main/canvas_item.cpp b/scene/main/canvas_item.cpp
index 916833c9a7..232c522a47 100644
--- a/scene/main/canvas_item.cpp
+++ b/scene/main/canvas_item.cpp
@@ -274,6 +274,7 @@ void CanvasItem::_exit_canvas() {
 void CanvasItem::_notification(int p_what) {
 	switch (p_what) {
 		case NOTIFICATION_ENTER_TREE: {
+			ERR_FAIL_COND(!is_inside_tree());
 			_update_texture_filter_changed(false);
 			_update_texture_repeat_changed(false);