diff --git a/documentation/docs/98-reference/.generated/compile-errors.md b/documentation/docs/98-reference/.generated/compile-errors.md
index 43493993b8..c6e2674b88 100644
--- a/documentation/docs/98-reference/.generated/compile-errors.md
+++ b/documentation/docs/98-reference/.generated/compile-errors.md
@@ -605,6 +605,12 @@ Cannot use `await` in deriveds and template expressions, or at the top level of
 Imports of `svelte/internal/*` are forbidden. It contains private runtime code which is subject to change without notice. If you're importing from `svelte/internal/*` to work around a limitation of Svelte, please open an issue at https://github.com/sveltejs/svelte and explain your use case
 ```
 
+### incompatible_with_custom_renderer
+
+```
+%message% is not compatible with `customRenderer`
+```
+
 ### inspect_trace_generator
 
 ```
diff --git a/packages/svelte/messages/compile-errors/template.md b/packages/svelte/messages/compile-errors/template.md
index 6aa4335c11..d53cd9e554 100644
--- a/packages/svelte/messages/compile-errors/template.md
+++ b/packages/svelte/messages/compile-errors/template.md
@@ -263,6 +263,10 @@ The same applies to components:
 
 > `<%name%>` does not support non-event attributes or spread attributes
 
+## incompatible_with_custom_renderer
+
+> %message% is not compatible with `customRenderer`
+
 ## js_parse_error
 
 > %message%
diff --git a/packages/svelte/src/compiler/errors.js b/packages/svelte/src/compiler/errors.js
index b97879ccee..897013353c 100644
--- a/packages/svelte/src/compiler/errors.js
+++ b/packages/svelte/src/compiler/errors.js
@@ -1185,6 +1185,16 @@ export function illegal_element_attribute(node, name) {
 	e(node, 'illegal_element_attribute', `\`<${name}>\` does not support non-event attributes or spread attributes\nhttps://svelte.dev/e/illegal_element_attribute`);
 }
 
+/**
+ * %message% is not compatible with `customRenderer`
+ * @param {null | number | NodeLike} node
+ * @param {string} message
+ * @returns {never}
+ */
+export function incompatible_with_custom_renderer(node, message) {
+	e(node, 'incompatible_with_custom_renderer', `${message} is not compatible with \`customRenderer\`\nhttps://svelte.dev/e/incompatible_with_custom_renderer`);
+}
+
 /**
  * %message%
  * @param {null | number | NodeLike} node
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteBody.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteBody.js
index 82bc592c14..1bd353b689 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteBody.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteBody.js
@@ -9,6 +9,10 @@ import { disallow_children } from './shared/special-element.js';
  * @param {Context} context
  */
 export function SvelteBody(node, context) {
+	if (context.state.analysis.custom_renderer) {
+		e.incompatible_with_custom_renderer(node, '`<svelte:body>`');
+	}
+
 	disallow_children(node);
 	for (const attribute of node.attributes) {
 		if (
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteDocument.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteDocument.js
index fe54ebf30d..067a228692 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteDocument.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteDocument.js
@@ -9,6 +9,10 @@ import { is_event_attribute } from '../../../utils/ast.js';
  * @param {Context} context
  */
 export function SvelteDocument(node, context) {
+	if (context.state.analysis.custom_renderer) {
+		e.incompatible_with_custom_renderer(node, '`<svelte:document>`');
+	}
+
 	disallow_children(node);
 
 	for (const attribute of node.attributes) {
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteHead.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteHead.js
index 5a3ed44f20..253074e6a7 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteHead.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteHead.js
@@ -8,6 +8,10 @@ import { mark_subtree_dynamic } from './shared/fragment.js';
  * @param {Context} context
  */
 export function SvelteHead(node, context) {
+	if (context.state.analysis.custom_renderer) {
+		e.incompatible_with_custom_renderer(node, '`<svelte:head>`');
+	}
+
 	for (const attribute of node.attributes) {
 		e.svelte_head_illegal_attribute(attribute);
 	}
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteWindow.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteWindow.js
index 20f5abc5d6..ffaaa45258 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteWindow.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteWindow.js
@@ -9,6 +9,10 @@ import { is_event_attribute } from '../../../utils/ast.js';
  * @param {Context} context
  */
 export function SvelteWindow(node, context) {
+	if (context.state.analysis.custom_renderer) {
+		e.incompatible_with_custom_renderer(node, '`<svelte:window>`');
+	}
+
 	disallow_children(node);
 
 	for (const attribute of node.attributes) {
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/transform-template/index.js b/packages/svelte/src/compiler/phases/3-transform/client/transform-template/index.js
index 3dcc8c228a..b81746a0e5 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/transform-template/index.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/transform-template/index.js
@@ -51,7 +51,7 @@ export function transform_template(state, namespace, flags = 0) {
 		flags ? b.literal(flags) : undefined
 	);
 
-	if (state.template.contains_script_tag) {
+	if (state.template.contains_script_tag && !state.analysis.custom_renderer) {
 		call = b.call(`$.with_script`, call);
 	}
 
diff --git a/packages/svelte/src/internal/client/dom/blocks/svelte-head.js b/packages/svelte/src/internal/client/dom/blocks/svelte-head.js
index 11c949f083..acdd5fa458 100644
--- a/packages/svelte/src/internal/client/dom/blocks/svelte-head.js
+++ b/packages/svelte/src/internal/client/dom/blocks/svelte-head.js
@@ -18,7 +18,6 @@ import { COMMENT_NODE, EFFECT_PRESERVED, HEAD_EFFECT } from '#client/constants';
  * @returns {void}
  */
 export function head(hash, render_fn) {
-	// TODO RENDERER: throw in case we are using custom renderers as this rely on the head element
 	// The head function may be called after the first hydration pass and ssr comment nodes may still be present,
 	// therefore we need to skip that when we detect that we're not in hydration mode.
 	let previous_hydrate_node = null;
diff --git a/packages/svelte/tests/custom-renderers/samples/svelte-body/_config.js b/packages/svelte/tests/custom-renderers/samples/svelte-body/_config.js
new file mode 100644
index 0000000000..0756c1c397
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/svelte-body/_config.js
@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+	compile_error: '`<svelte:body>` is not compatible with `customRenderer`'
+});
diff --git a/packages/svelte/tests/custom-renderers/samples/svelte-body/main.svelte b/packages/svelte/tests/custom-renderers/samples/svelte-body/main.svelte
new file mode 100644
index 0000000000..d1377e8ca0
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/svelte-body/main.svelte
@@ -0,0 +1 @@
+<svelte:body></svelte:body>
diff --git a/packages/svelte/tests/custom-renderers/samples/svelte-document/_config.js b/packages/svelte/tests/custom-renderers/samples/svelte-document/_config.js
new file mode 100644
index 0000000000..4ec406039a
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/svelte-document/_config.js
@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+	compile_error: '`<svelte:document>` is not compatible with `customRenderer`'
+});
diff --git a/packages/svelte/tests/custom-renderers/samples/svelte-document/main.svelte b/packages/svelte/tests/custom-renderers/samples/svelte-document/main.svelte
new file mode 100644
index 0000000000..f0dc6c5633
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/svelte-document/main.svelte
@@ -0,0 +1 @@
+<svelte:document></svelte:document>
diff --git a/packages/svelte/tests/custom-renderers/samples/svelte-head/_config.js b/packages/svelte/tests/custom-renderers/samples/svelte-head/_config.js
new file mode 100644
index 0000000000..3a5c5d34cb
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/svelte-head/_config.js
@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+	compile_error: '`<svelte:head>` is not compatible with `customRenderer`'
+});
diff --git a/packages/svelte/tests/custom-renderers/samples/svelte-head/main.svelte b/packages/svelte/tests/custom-renderers/samples/svelte-head/main.svelte
new file mode 100644
index 0000000000..cd354a4c07
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/svelte-head/main.svelte
@@ -0,0 +1,9 @@
+<script>
+	let color = $state('red');
+</script>
+
+<svelte:head>
+	<script>
+		console.log('hello from script');
+	</script>
+</svelte:head>
diff --git a/packages/svelte/tests/custom-renderers/samples/svelte-window/_config.js b/packages/svelte/tests/custom-renderers/samples/svelte-window/_config.js
new file mode 100644
index 0000000000..f84268ca2e
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/svelte-window/_config.js
@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+	compile_error: '`<svelte:window>` is not compatible with `customRenderer`'
+});
diff --git a/packages/svelte/tests/custom-renderers/samples/svelte-window/main.svelte b/packages/svelte/tests/custom-renderers/samples/svelte-window/main.svelte
new file mode 100644
index 0000000000..47dd4baa23
--- /dev/null
+++ b/packages/svelte/tests/custom-renderers/samples/svelte-window/main.svelte
@@ -0,0 +1 @@
+<svelte:window></svelte:window>