diff --git a/packages/angular/build/src/builders/dev-server/vite-server.ts b/packages/angular/build/src/builders/dev-server/vite-server.ts
index cca66df4a606..07bb397f738a 100644
--- a/packages/angular/build/src/builders/dev-server/vite-server.ts
+++ b/packages/angular/build/src/builders/dev-server/vite-server.ts
@@ -482,6 +482,15 @@ export async function setupServer(
     css: {
       devSourcemap: true,
     },
+    // Ensure custom 'file' loader build option entries are handled by Vite in application code that
+    // reference third-party libraries. Relative usage is handled directly by the build and not Vite.
+    // Only 'file' loader entries are currently supported directly by Vite.
+    assetsInclude:
+      prebundleLoaderExtensions &&
+      Object.entries(prebundleLoaderExtensions)
+        .filter(([, value]) => value === 'file')
+        // Create a file extension glob for each key
+        .map(([key]) => '*' + key),
     // Vite will normalize the `base` option by adding a leading slash.
     base: serverOptions.servePath,
     resolve: {
diff --git a/packages/angular/build/src/tools/esbuild/external-packages-plugin.ts b/packages/angular/build/src/tools/esbuild/external-packages-plugin.ts
index fda108b9841c..5344e9abe33f 100644
--- a/packages/angular/build/src/tools/esbuild/external-packages-plugin.ts
+++ b/packages/angular/build/src/tools/esbuild/external-packages-plugin.ts
@@ -24,8 +24,13 @@ export function createExternalPackagesPlugin(options?: { exclude?: string[] }):
   return {
     name: 'angular-external-packages',
     setup(build) {
+      // Find all loader keys that are not using the 'file' loader.
+      // The 'file' loader is automatically handled by Vite and does not need exclusion.
       const loaderOptionKeys =
-        build.initialOptions.loader && Object.keys(build.initialOptions.loader);
+        build.initialOptions.loader &&
+        Object.entries(build.initialOptions.loader)
+          .filter(([, value]) => value !== 'file')
+          .map(([key]) => key);
 
       // Safe to use native packages external option if no loader options or exclusions present
       if (!exclusions && !loaderOptionKeys?.length) {