diff --git a/src/app/app.ts b/src/app/app.ts
index b05143fd..38d753bd 100644
--- a/src/app/app.ts
+++ b/src/app/app.ts
@@ -28,6 +28,8 @@ export class App<
   P = any,
   E = any
 > extends TemplateSet {
+  static validateTarget = validateTarget;
+
   Root: ComponentConstructor<P, E>;
   props: P;
   env: E;
@@ -49,7 +51,7 @@ export class App<
   }
 
   mount(target: HTMLElement, options?: MountOptions): Promise<Component<P, E> & InstanceType<T>> {
-    validateTarget(target);
+    App.validateTarget(target);
     const node = this.makeNode(this.Root, this.props);
     const prom = this.mountNode(node, target, options);
     this.root = node;
diff --git a/src/component/fibers.ts b/src/component/fibers.ts
index 8c9ce42c..b944c4fd 100644
--- a/src/component/fibers.ts
+++ b/src/component/fibers.ts
@@ -1,5 +1,4 @@
 import { BDom, mount } from "../blockdom";
-import { validateTarget } from "../utils";
 import type { ComponentNode } from "./component_node";
 import { fibersInError, handleError } from "./error_handling";
 import { STATUS } from "./status";
@@ -159,8 +158,8 @@ export class MountFiber extends RootFiber {
   complete() {
     let current: Fiber | undefined = this;
     try {
-      validateTarget(this.target);
       const node = this.node;
+      (node.app.constructor as any).validateTarget(this.target);
       if (node.bdom) {
         // this is a complicated situation: if we mount a fiber with an existing
         // bdom, this means that this same fiber was already completed, mounted,
diff --git a/tests/components/__snapshots__/basics.test.ts.snap b/tests/components/__snapshots__/basics.test.ts.snap
index 07c1c560..5d05da30 100644
--- a/tests/components/__snapshots__/basics.test.ts.snap
+++ b/tests/components/__snapshots__/basics.test.ts.snap
@@ -81,7 +81,7 @@ exports[`basics a class component inside a class component, no external dom 2`]
 }"
 `;
 
-exports[`basics a component cannot be mounted in a detached node (even if node is detached later 1`] = `
+exports[`basics a component cannot be mounted in a detached node (even if node is detached later) 1`] = `
 "function anonymous(bdom, helpers
 ) {
   let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;