diff --git a/packages/release-manifest/src/manifest.ts b/packages/release-manifest/src/manifest.ts
index 1120073afb..564809fdee 100644
--- a/packages/release-manifest/src/manifest.ts
+++ b/packages/release-manifest/src/manifest.ts
@@ -23,6 +23,7 @@ const VERSIONS_DOMAIN = 'https://versions.backstage.io';
  * @public
  */
 export type ReleaseManifest = {
+  releaseVersion: string;
   packages: { name: string; version: string }[];
 };
 
@@ -41,7 +42,9 @@ export type GetByVersionOptions = {
 export async function getByVersion(
   options: GetByVersionOptions,
 ): Promise<ReleaseManifest> {
-  const url = `${VERSIONS_DOMAIN}/v1/releases/${options.version}/manifest.json`;
+  const url = `${VERSIONS_DOMAIN}/v1/releases/${encodeURIComponent(
+    options.version,
+  )}/manifest.json`;
   const response = await fetch(url);
   if (response.status === 404) {
     throw new Error(`No release found for ${options.version} version`);
@@ -69,7 +72,9 @@ export type GetByReleaseLineOptions = {
 export async function getByReleaseLine(
   options: GetByReleaseLineOptions,
 ): Promise<ReleaseManifest> {
-  const url = `${VERSIONS_DOMAIN}/v1/tags/${options.releaseLine}/manifest.json`;
+  const url = `${VERSIONS_DOMAIN}/v1/tags/${encodeURIComponent(
+    options.releaseLine,
+  )}/manifest.json`;
   const response = await fetch(url);
   if (response.status === 404) {
     throw new Error(`No '${options.releaseLine}' release line found`);