diff --git a/.github/workflows/publish-release.js b/.github/workflows/publish-release.js
index 689bf1e..5713afb 100644
--- a/.github/workflows/publish-release.js
+++ b/.github/workflows/publish-release.js
@@ -16,6 +16,25 @@ module.exports = /*async*/ ({github, context, core}) => {
         const version = context.payload.inputs.version
         const tag = "v" + version
         console.log(`Validate version '${version}'.`)
+
+        // git branch must exist
+        try {
+            const ref = await restapi.git.getRef({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                ref: 'refs/heads/release' + version
+            })
+            if (ref == null) {
+                core.setFailed(`Could not find branch 'release/${version}'.`)
+                return    
+            }
+        }
+        catch (error) {
+            core.setFailed(`Could not find branch 'release/${version}'.`)
+            return
+        }
+
+        // github release must exist and not be published yet
         try {
             const release = restapi.repos.getReleaseByTag({
                 owner: context.repo.owner,
@@ -36,6 +55,8 @@ module.exports = /*async*/ ({github, context, core}) => {
             core.setFailed(`Could not find a GitHub release for tag '${tag}'.`)
             return
         }
+
+        // tag must not exist
         try {
             const ref = await restapi.git.getRef({
                 owner: context.repo.owner,
@@ -49,7 +70,7 @@ module.exports = /*async*/ ({github, context, core}) => {
             // this is expected - the tag should not exist
         }
 
-        console.log(`Found a yet-unpublished GitHub Release for tag '${tag}' which does not exist yet.`)
+        console.log(`Found branch 'release/${version}', a yet-unpublished GitHub Release for tag '${tag}' which does not exist yet.`)
     }   
 
     function test() {