diff --git a/.changeset/gold-colts-change.md b/.changeset/gold-colts-change.md
new file mode 100644
index 00000000000..1bbdbe5ea5b
--- /dev/null
+++ b/.changeset/gold-colts-change.md
@@ -0,0 +1,5 @@
+---
+'@builder.io/qwik': patch
+---
+
+FIX: assetsDir and debug:true will no longer break your application.
diff --git a/packages/qwik/src/optimizer/src/plugins/rollup.ts b/packages/qwik/src/optimizer/src/plugins/rollup.ts
index ba3002f4d24..b6c695bcf48 100644
--- a/packages/qwik/src/optimizer/src/plugins/rollup.ts
+++ b/packages/qwik/src/optimizer/src/plugins/rollup.ts
@@ -194,12 +194,22 @@ export function normalizeRollupOutputOptionsObject(
         return `build/${sanitized}.js`;
       };
     }
-    // client production output
+    // client development/debug output
+    const getFilePath = (fileNamePattern: string | ((info: Rollup.PreRenderedChunk) => string)) =>
+      typeof fileNamePattern === 'string'
+        ? useAssetsDir
+          ? `${opts.assetsDir}/${fileNamePattern}`
+          : fileNamePattern
+        : useAssetsDir
+          ? (chunkInfo: Rollup.PreRenderedChunk) =>
+              `${opts.assetsDir}/${fileNamePattern(chunkInfo)}`
+          : (chunkInfo: Rollup.PreRenderedChunk) => fileNamePattern(chunkInfo);
+
     if (!outputOpts.entryFileNames) {
-      outputOpts.entryFileNames = useAssetsDir ? `${opts.assetsDir}/${fileName}` : fileName;
+      outputOpts.entryFileNames = getFilePath(fileName);
     }
     if (!outputOpts.chunkFileNames) {
-      outputOpts.chunkFileNames = useAssetsDir ? `${opts.assetsDir}/${fileName}` : fileName;
+      outputOpts.chunkFileNames = getFilePath(fileName);
     }
   } else if (opts.buildMode === 'production') {
     // server production output