diff --git a/src/lib/learn-client/api/collection/fetch-product-collections.ts b/src/lib/learn-client/api/collection/fetch-product-collections.ts
index 278cc70e6c..ca18b1ae62 100644
--- a/src/lib/learn-client/api/collection/fetch-product-collections.ts
+++ b/src/lib/learn-client/api/collection/fetch-product-collections.ts
@@ -8,6 +8,7 @@ import {
 	uuid,
 	ProductOption,
 	AllCollectionsProductOptions,
+	ThemeOption,
 } from 'lib/learn-client/types'
 import { get, toError } from '../../index'
 
@@ -27,18 +28,29 @@ export const PRODUCT_COLLECTION_API_ROUTE = (
  * includes filtering for theme
  */
 export async function fetchAllCollectionsByProduct(
-	product: AllCollectionsProductOptions
+	product: AllCollectionsProductOptions,
+	/**
+	 * All `ProductOption` values except `sentinel` can be used as "theme" options.
+	 * Theme is mainly used to add a product logo to various UI elements, and
+	 * since Sentinel doesn't have a logo, it's not a valid theme option.
+	 *
+	 * Note: an alternative here might be to implement a `theme` option for
+	 * Sentinel, and for now, set it to render a HashiCorp logo. This might
+	 * be a more future-proof approach. This would require updates to `learn-api`:
+	 * https://github.com/hashicorp/learn-api/blob/main/src/models/collection.ts#L17
+	 */
+	theme?: Exclude<ProductOption, 'sentinel'> | ThemeOption
 ): Promise<Collection[]> {
 	const baseUrl = PRODUCT_COLLECTION_API_ROUTE(product.slug)
 	let route = baseUrl
 
 	if (product.sidebarSort) {
-		const params = new URLSearchParams([
-			['topLevelCategorySort', 'true'],
-			['theme', product.slug],
-		])
-
-		route = baseUrl + `?${params.toString()}`
+		const params = []
+		params.push(['topLevelCategorySort', 'true'])
+		if (theme) {
+			params.push(['theme', theme])
+		}
+		route = baseUrl + `?${new URLSearchParams(params).toString()}`
 	}
 
 	const getProductCollectionsRes = await get(route)
diff --git a/src/lib/learn-client/api/collection/index.ts b/src/lib/learn-client/api/collection/index.ts
index 54e88c382a..8a84776df6 100644
--- a/src/lib/learn-client/api/collection/index.ts
+++ b/src/lib/learn-client/api/collection/index.ts
@@ -80,8 +80,19 @@ export async function getAllCollections(
 
 	// check if the product option is valid, i.e. not 'cloud' or 'hashicorp'
 	if (options?.product && themeIsProduct(options.product.slug)) {
-		const allCollections = await fetchAllCollectionsByProduct(options.product)
-
+		/**
+		 * Sentinel cannot use "theme", as the `learn-api` doesn't support a
+		 * `sentinel` theme value. We expect authors to use `theme: hashicorp`
+		 * on Sentinel collections. We could provide "hashicorp" here instead
+		 * of `null`, but that might result in unexpected filtering out if
+		 * authors use a different `theme` for any Sentinel collection.
+		 */
+		const theme =
+			options.product.slug === 'sentinel' ? null : options.product.slug
+		const allCollections = await fetchAllCollectionsByProduct(
+			options.product,
+			theme
+		)
 		collections = [...allCollections]
 	} else {
 		const limit = options?.limit?.toString()