diff --git a/crates/spa/src/vite.rs b/crates/spa/src/vite.rs
index e40233595..b488bea6b 100644
--- a/crates/spa/src/vite.rs
+++ b/crates/spa/src/vite.rs
@@ -47,48 +47,6 @@ pub struct Manifest {
     inner: HashMap<Utf8PathBuf, ManifestEntry>,
 }
 
-impl Manifest {
-    /// Produce a sample manifest for use in reproducible sample renders.
-    #[must_use]
-    #[allow(clippy::missing_panics_doc)]
-    pub fn sample() -> Self {
-        let mut inner = HashMap::new();
-
-        for name in &[
-            "src/shared.css",
-            "src/templates.css",
-            "src/main.tsx",
-            "src/swagger.ts",
-        ] {
-            inner.insert(
-                name.parse().unwrap(),
-                ManifestEntry {
-                    name: None,
-                    names: None,
-                    src: None,
-                    // Construct a fake but slightly plausible dummy asset name.
-                    file: name
-                        .replace('/', "__")
-                        .replace('.', "-XXXXX.")
-                        .replace(".tsx", ".js")
-                        .replace(".ts", ".js")
-                        .parse()
-                        .unwrap(),
-                    css: None,
-                    assets: None,
-                    is_entry: None,
-                    is_dynamic_entry: None,
-                    imports: None,
-                    dynamic_imports: None,
-                    integrity: None,
-                },
-            );
-        }
-
-        Manifest { inner }
-    }
-}
-
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
 enum FileType {
     Script,
diff --git a/crates/templates/src/functions.rs b/crates/templates/src/functions.rs
index 82b79133a..9d764e032 100644
--- a/crates/templates/src/functions.rs
+++ b/crates/templates/src/functions.rs
@@ -30,7 +30,7 @@ use url::Url;
 pub fn register(
     env: &mut minijinja::Environment,
     url_builder: UrlBuilder,
-    vite_manifest: ViteManifest,
+    vite_manifest: Option<ViteManifest>,
     translator: Arc<Translator>,
 ) {
     env.set_unknown_method_callback(minijinja_contrib::pycompat::unknown_method_callback);
@@ -43,13 +43,17 @@ pub fn register(
     env.add_filter("parse_user_agent", filter_parse_user_agent);
     env.add_function("add_params_to_url", function_add_params_to_url);
     env.add_function("counter", || Ok(Value::from_object(Counter::default())));
-    env.add_global(
-        "include_asset",
-        Value::from_object(IncludeAsset {
-            url_builder: url_builder.clone(),
-            vite_manifest,
-        }),
-    );
+    if let Some(vite_manifest) = vite_manifest {
+        env.add_global(
+            "include_asset",
+            Value::from_object(IncludeAsset {
+                url_builder: url_builder.clone(),
+                vite_manifest,
+            }),
+        );
+    } else {
+        env.add_global("include_asset", Value::from_object(FakeIncludeAsset {}));
+    }
     env.add_global(
         "translator",
         Value::from_object(TranslatorFunc { translator }),
@@ -456,6 +460,30 @@ impl Object for IncludeAsset {
     }
 }
 
+struct FakeIncludeAsset {}
+
+impl std::fmt::Debug for FakeIncludeAsset {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("FakeIncludeAsset").finish()
+    }
+}
+
+impl std::fmt::Display for FakeIncludeAsset {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("fake_include_asset")
+    }
+}
+
+impl Object for FakeIncludeAsset {
+    fn call(self: &Arc<Self>, _state: &State, args: &[Value]) -> Result<Value, Error> {
+        let (path,): (&str,) = from_args(args)?;
+
+        Ok(Value::from_safe_string(format!(
+            "<!--- include_asset {path} -->"
+        )))
+    }
+}
+
 #[derive(Debug, Default)]
 struct Counter {
     count: AtomicUsize,
diff --git a/crates/templates/src/lib.rs b/crates/templates/src/lib.rs
index ec23bfdb4..32a41e8b2 100644
--- a/crates/templates/src/lib.rs
+++ b/crates/templates/src/lib.rs
@@ -206,10 +206,12 @@ impl Templates {
                 .await
                 .map_err(TemplateLoadingError::ViteManifestIO)?;
 
-            serde_json::from_slice::<ViteManifest>(&raw_vite_manifest)
-                .map_err(TemplateLoadingError::ViteManifest)?
+            Some(
+                serde_json::from_slice::<ViteManifest>(&raw_vite_manifest)
+                    .map_err(TemplateLoadingError::ViteManifest)?,
+            )
         } else {
-            ViteManifest::sample()
+            None
         };
 
         // Parse it