diff --git a/app/assets/javascripts/discourse-common/addon/resolver.js b/app/assets/javascripts/discourse-common/addon/resolver.js
index d8356d917e2..6cfbded2825 100644
--- a/app/assets/javascripts/discourse-common/addon/resolver.js
+++ b/app/assets/javascripts/discourse-common/addon/resolver.js
@@ -115,10 +115,6 @@ const DEPRECATED_MODULES = new Map(
   })
 );
 
-export function normalizeDeprecatedModule(name) {
-  return DEPRECATED_MODULES.get(name)?.newName || name;
-}
-
 export function setResolverOption(name, value) {
   _options[name] = value;
 }
diff --git a/app/assets/javascripts/discourse/app/lib/plugin-api.gjs b/app/assets/javascripts/discourse/app/lib/plugin-api.gjs
index 9ed9a97e8c3..a1ce362174d 100644
--- a/app/assets/javascripts/discourse/app/lib/plugin-api.gjs
+++ b/app/assets/javascripts/discourse/app/lib/plugin-api.gjs
@@ -159,7 +159,6 @@ import {
   registerIconRenderer,
   replaceIcon,
 } from "discourse-common/lib/icon-library";
-import { normalizeDeprecatedModule } from "discourse-common/resolver";
 import { addImageWrapperButton } from "discourse-markdown-it/features/image-controls";
 import { CUSTOM_USER_SEARCH_OPTIONS } from "select-kit/components/user-chooser";
 import { modifySelectKit } from "select-kit/mixins/plugin-api";
@@ -254,26 +253,27 @@ class PluginApi {
 
   _resolveClass(resolverName, opts) {
     opts = opts || {};
-
+    const normalized = this.container.registry.normalize(resolverName);
     if (
-      this.container.cache[normalizeDeprecatedModule(resolverName)] ||
-      (resolverName === "model:user" &&
+      this.container.cache[normalized] ||
+      (normalized === "model:user" &&
         this.container.lookup("service:current-user"))
     ) {
       // eslint-disable-next-line no-console
-      console.warn(
+      console.error(
         consolePrefix(),
         `Attempted to modify "${resolverName}", but it was already initialized earlier in the boot process (e.g. via a lookup()). Remove that lookup, or move the modifyClass call earlier in the boot process for changes to take effect. https://meta.discourse.org/t/262064`
       );
+      return;
     }
 
-    const klass = this.container.factoryFor(resolverName);
+    const klass = this.container.factoryFor(normalized);
     if (!klass) {
       if (!opts.ignoreMissing) {
         // eslint-disable-next-line no-console
         console.warn(
           consolePrefix(),
-          `"${resolverName}" was not found by modifyClass`
+          `"${normalized}" was not found by modifyClass`
         );
       }
       return;