diff --git a/dist/create-release-branch-main.js b/dist/create-release-branch-main.js
index 25dbf87..4361dea 100644
--- a/dist/create-release-branch-main.js
+++ b/dist/create-release-branch-main.js
@@ -24851,7 +24851,7 @@ function setup() {
         version: version === "" ? undefined : version,
         liveRun,
         repo,
-        branch,
+        branch: branch === "" ? undefined : branch,
         githubToken,
         dryRunHistorySize: dryRunHistorySize == "" ? DEFAULT_DRY_RUN_HISTORY_SIZE : Number(dryRunHistorySize),
     };
diff --git a/src/create-release-branch.ts b/src/create-release-branch.ts
index 32426ba..3c80467 100644
--- a/src/create-release-branch.ts
+++ b/src/create-release-branch.ts
@@ -28,7 +28,7 @@ export function setup(): Input {
     version: version === "" ? undefined : version,
     liveRun,
     repo,
-    branch,
+    branch: branch === "" ? undefined : branch,
     githubToken,
     dryRunHistorySize: dryRunHistorySize == "" ? DEFAULT_DRY_RUN_HISTORY_SIZE : Number(dryRunHistorySize),
   };