diff --git a/packages/core/src/compiler/compositionScoping.test.ts b/packages/core/src/compiler/compositionScoping.test.ts
index 07c7faf01..5a0a0cd3a 100644
--- a/packages/core/src/compiler/compositionScoping.test.ts
+++ b/packages/core/src/compiler/compositionScoping.test.ts
@@ -1,6 +1,10 @@
 import { describe, expect, it, vi } from "vitest";
 import { parseHTML } from "linkedom";
-import { scopeCssToComposition, wrapScopedCompositionScript } from "./compositionScoping";
+import {
+  scopeCssToComposition,
+  wrapInlineScriptWithErrorBoundary,
+  wrapScopedCompositionScript,
+} from "./compositionScoping";
 
 describe("composition scoping", () => {
   it("scopes regular selectors while preserving global at-rules", () => {
@@ -568,6 +572,26 @@ window.__afterTimeline = window.__timelines.scene;
     expect(scoped).toContain('[data-composition-id="chrome-overlay"] .child-element');
   });
 
+  it("wraps scoped composition script source as a string literal", () => {
+    const wrapped = wrapScopedCompositionScript(
+      'window.payload = "</script><script>window.pwned = true;</script>";',
+      "scene",
+    );
+
+    expect(wrapped).toContain('Function("document", "gsap", "window", "__hyperframes", ');
+    expect(wrapped).toContain('\\"</script><script>window.pwned = true;</script>\\"');
+  });
+
+  it("wraps unscoped composition script source as a string literal", () => {
+    const wrapped = wrapInlineScriptWithErrorBoundary(
+      'window.payload = "</script><script>window.pwned = true;</script>";',
+      "[HyperFrames] composition script error:",
+    );
+
+    expect(wrapped).toContain("Function(");
+    expect(wrapped).toContain('\\"</script><script>window.pwned = true;</script>\\"');
+  });
+
   it("rewrites #id CSS selectors to [data-hf-authored-id] when authoredRootId is provided", () => {
     const scoped = scopeCssToComposition(
       `#intro { background: #111; }
diff --git a/packages/core/src/compiler/compositionScoping.ts b/packages/core/src/compiler/compositionScoping.ts
index 280fe5df8..72e9cbbf8 100644
--- a/packages/core/src/compiler/compositionScoping.ts
+++ b/packages/core/src/compiler/compositionScoping.ts
@@ -216,6 +216,7 @@ export function wrapScopedCompositionScript(
   const authoredRootIdFormsLiteral = JSON.stringify(
     getAuthoredRootIdSelectorForms(authoredRootId?.trim() || ""),
   );
+  const sourceLiteral = JSON.stringify(source);
   return `(function(){
   var __hfCompId = ${compositionIdLiteral};
   var __hfTimelineCompId = ${timelineCompositionIdLiteral};
@@ -485,9 +486,8 @@ export function wrapScopedCompositionScript(
       });
   var __hfRun = function() {
     try {
-      (function(document, gsap, window, __hyperframes) {
-${source}
-      }).call(window, __hfScopedDocument, __hfScopedGsap, __hfScopedWindow, __hfScopedHyperframes);
+      var __hfScript = Function("document", "gsap", "window", "__hyperframes", ${sourceLiteral});
+      __hfScript.call(window, __hfScopedDocument, __hfScopedGsap, __hfScopedWindow, __hfScopedHyperframes);
     } catch (_err) {
       console.error(__hfErrorLabel, __hfCompId, _err);
     }
@@ -496,3 +496,7 @@ ${source}
   __hfRun();
 })();`;
 }
+
+export function wrapInlineScriptWithErrorBoundary(source: string, errorLabel: string): string {
+  return `(function(){ try { Function(${JSON.stringify(source)}).call(window); } catch (_err) { console.error(${JSON.stringify(errorLabel)}, _err); } })();`;
+}
diff --git a/packages/core/src/compiler/htmlBundler.test.ts b/packages/core/src/compiler/htmlBundler.test.ts
index 8981c1ea5..f955ef5ea 100644
--- a/packages/core/src/compiler/htmlBundler.test.ts
+++ b/packages/core/src/compiler/htmlBundler.test.ts
@@ -758,7 +758,8 @@ describe("bundleToSingleHtml", () => {
     expect(bundled).toContain('[data-composition-id="scene"] .title { color: red; }');
     expect(bundled).toContain("new Proxy(window.document");
     expect(bundled).toContain("new Proxy(__hfBaseGsap");
-    expect(bundled).toContain('tl.to(".title"');
+    expect(bundled).toContain('Function("document", "gsap", "window", "__hyperframes",');
+    expect(bundled).toContain("tl.to('.title'");
   });
 
   it("isolates sibling instances of the same external sub-composition", async () => {
diff --git a/packages/core/src/compiler/htmlBundler.ts b/packages/core/src/compiler/htmlBundler.ts
index f4442a955..de590c850 100644
--- a/packages/core/src/compiler/htmlBundler.ts
+++ b/packages/core/src/compiler/htmlBundler.ts
@@ -8,7 +8,11 @@ import {
   stripEmbeddedRuntimeScripts,
 } from "./htmlDocument";
 // rewriteSubCompPaths functions are used by inlineSubCompositions (shared module)
-import { scopeCssToComposition, wrapScopedCompositionScript } from "./compositionScoping";
+import {
+  scopeCssToComposition,
+  wrapInlineScriptWithErrorBoundary,
+  wrapScopedCompositionScript,
+} from "./compositionScoping";
 import { validateHyperframeHtmlContract } from "./staticGuard";
 import { getHyperframeRuntimeScript } from "../generated/runtime-inline";
 import { readDeclaredDefaults } from "../runtime/getVariables";
@@ -824,7 +828,10 @@ export async function bundleToSingleHtml(
                     runtimeCompId || compId,
                     authoredRootId,
                   )
-                : `(function(){ try { ${scriptEl.textContent || ""} } catch (_err) { console.error('[HyperFrames] composition script error:', _err); } })();`,
+                : wrapInlineScriptWithErrorBoundary(
+                    scriptEl.textContent || "",
+                    "[HyperFrames] composition script error:",
+                  ),
             );
           }
           scriptEl.remove();
@@ -875,7 +882,10 @@ export async function bundleToSingleHtml(
                     runtimeScope,
                     runtimeCompId || compId,
                   )
-                : `(function(){ try { ${scriptEl.textContent || ""} } catch (_err) { console.error('[HyperFrames] composition script error:', _err); } })();`,
+                : wrapInlineScriptWithErrorBoundary(
+                    scriptEl.textContent || "",
+                    "[HyperFrames] composition script error:",
+                  ),
             );
           }
           scriptEl.remove();
diff --git a/packages/core/src/compiler/inlineSubCompositions.ts b/packages/core/src/compiler/inlineSubCompositions.ts
index 647e51988..00f09f268 100644
--- a/packages/core/src/compiler/inlineSubCompositions.ts
+++ b/packages/core/src/compiler/inlineSubCompositions.ts
@@ -13,7 +13,11 @@ import {
   rewriteCssAssetUrls,
   rewriteInlineStyleAssetUrls,
 } from "./rewriteSubCompPaths";
-import { scopeCssToComposition, wrapScopedCompositionScript } from "./compositionScoping";
+import {
+  scopeCssToComposition,
+  wrapInlineScriptWithErrorBoundary,
+  wrapScopedCompositionScript,
+} from "./compositionScoping";
 
 // ---------------------------------------------------------------------------
 // Public interface
@@ -287,7 +291,7 @@ export function inlineSubCompositions(
               runtimeCompId || scopeCompId,
               authoredRootId,
             )
-          : `(function(){ try { ${s.textContent || ""} } catch (_err) { console.error(${JSON.stringify(scriptErrorLabel)}, _err); } })();`;
+          : wrapInlineScriptWithErrorBoundary(s.textContent || "", scriptErrorLabel);
         scripts.push(wrappedScript);
         scriptItems.push({ kind: "inline", content: wrappedScript });
       }