diff --git a/dist/index.js b/dist/index.js
index da243b57..a16648d6 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -3875,7 +3875,7 @@ async function getChangesSinceMergeBase(baseRef, ref, initialFetchDepth) {
         let lastCommitCount = await getCommitCount();
         let depth = Math.max(lastCommitCount * 2, initialFetchDepth);
         while (!(await hasMergeBase())) {
-            await exec_1.default('git', ['fetch', `--depth=${depth}`, 'origin', `${baseRef}:${baseRef}`, `${ref}:${ref}`]);
+            await exec_1.default('git', ['fetch', `--depth=${depth}`, 'origin', `${baseRef}:${baseRef}`, `${ref}`]);
             const commitCount = await getCommitCount();
             if (commitCount === lastCommitCount) {
                 core.info('No more commits were fetched');
diff --git a/src/git.ts b/src/git.ts
index 2cfa8aeb..c58621fd 100644
--- a/src/git.ts
+++ b/src/git.ts
@@ -69,7 +69,7 @@ export async function getChangesSinceMergeBase(
     let lastCommitCount = await getCommitCount()
     let depth = Math.max(lastCommitCount * 2, initialFetchDepth)
     while (!(await hasMergeBase())) {
-      await exec('git', ['fetch', `--depth=${depth}`, 'origin', `${baseRef}:${baseRef}`, `${ref}:${ref}`])
+      await exec('git', ['fetch', `--depth=${depth}`, 'origin', `${baseRef}:${baseRef}`, `${ref}`])
       const commitCount = await getCommitCount()
       if (commitCount === lastCommitCount) {
         core.info('No more commits were fetched')