diff --git a/extensions/amp-facebook-comments/1.0/storybook/Basic.amp.js b/extensions/amp-facebook-comments/1.0/storybook/Basic.amp.js
index c4211604bd1b..28129c9d13da 100644
--- a/extensions/amp-facebook-comments/1.0/storybook/Basic.amp.js
+++ b/extensions/amp-facebook-comments/1.0/storybook/Basic.amp.js
@@ -51,7 +51,11 @@ export const _default = () => {
       data-locale={locale}
       data-numposts={numPosts}
       data-order-by={orderBy}
-    ></amp-facebook-comments>
+    >
+      <div placeholder>
+        <h1>Placeholder</h1>
+      </div>
+    </amp-facebook-comments>
   );
 };
 
diff --git a/src/preact/base-element.js b/src/preact/base-element.js
index b469e892bc30..46db3d10c73b 100644
--- a/src/preact/base-element.js
+++ b/src/preact/base-element.js
@@ -114,8 +114,11 @@ const SHADOW_CONTAINER_ATTRS = dict({
   'part': 'c',
 });
 
+/** @const {string} */
+const SERVICE_SLOT_NAME = 'i-amphtml-svc';
+
 /** @const {!JsonObject<string, string>} */
-const SERVICE_SLOT_ATTRS = dict({'name': 'i-amphtml-svc'});
+const SERVICE_SLOT_ATTRS = dict({'name': SERVICE_SLOT_NAME});
 
 /**
  * The same as `applyFillContent`, but inside the shadow.
@@ -624,6 +627,8 @@ export class PreactBaseElement extends AMP.BaseElement {
             SERVICE_SLOT_ATTRS
           );
           shadowRoot.appendChild(serviceSlot);
+          this.getPlaceholder()?.setAttribute('slot', SERVICE_SLOT_NAME);
+          this.getFallback()?.setAttribute('slot', SERVICE_SLOT_NAME);
         }
         this.container_ = container;
 
diff --git a/test/unit/preact/test-base-element-mapping.js b/test/unit/preact/test-base-element-mapping.js
index 9334295f3b1b..b71305e9f31f 100644
--- a/test/unit/preact/test-base-element-mapping.js
+++ b/test/unit/preact/test-base-element-mapping.js
@@ -351,6 +351,8 @@ describes.realWin('PreactBaseElement', spec, (env) => {
       element = html`
         <amp-preact layout="fixed" width="100" height="100">
           <div id="child1"></div>
+          <div placeholder>foo</div>
+          <div fallback>bar</div>
         </amp-preact>
       `;
     });
@@ -373,6 +375,23 @@ describes.realWin('PreactBaseElement', spec, (env) => {
       ).to.have.lengthOf(1);
     });
 
+    it('should pass placeholder and fallback elements to service slot', async () => {
+      doc.body.appendChild(element);
+      await element.buildInternal();
+      await waitFor(() => component.callCount > 0, 'component rendered');
+      const serviceSlot = element.shadowRoot.querySelectorAll(
+        'slot[name="i-amphtml-svc"]'
+      );
+      expect(serviceSlot).to.have.lengthOf(1);
+      const placeholder = element.querySelector('[placeholder]');
+      const fallback = element.querySelector('[fallback]');
+      expect(placeholder.getAttribute('slot')).to.equal('i-amphtml-svc');
+      expect(fallback.getAttribute('slot')).to.equal('i-amphtml-svc');
+      expect(serviceSlot[0].assignedElements()).to.have.lengthOf(2);
+      expect(serviceSlot[0].assignedElements()[0]).to.equal(placeholder);
+      expect(serviceSlot[0].assignedElements()[1]).to.equal(fallback);
+    });
+
     describe('SSR', () => {
       let shadowRoot, container;
       let componentEl, serviceSlotEl, styleEl;