diff --git a/scripts/update-theme.ts b/scripts/update-theme.ts
index cb4312d..fde7414 100755
--- a/scripts/update-theme.ts
+++ b/scripts/update-theme.ts
@@ -14,7 +14,7 @@ try {
   execSync('git fetch upstream', { stdio: 'inherit' })
 
   const beforeHash = execSync('git rev-parse HEAD', { encoding: 'utf8' }).trim()
-  execSync('git merge upstream/master', { stdio: 'inherit' })
+  execSync('git merge upstream/master --allow-unrelated-histories', { stdio: 'inherit' })
   const afterHash = execSync('git rev-parse HEAD', { encoding: 'utf8' }).trim()
 
   if (beforeHash === afterHash) {