diff --git a/tool/sync_default_gems.rb b/tool/sync_default_gems.rb
index 236c16a184..c6d64e9bd9 100644
--- a/tool/sync_default_gems.rb
+++ b/tool/sync_default_gems.rb
@@ -399,7 +399,7 @@ def sync_default_gems_with_commits(gem, ranges, edit: nil)
 
     prefix = "[#{(REPOSITORIES[gem.to_sym])}]".gsub(/\//, '\/')
     suffix = "https://github.com/#{(REPOSITORIES[gem.to_sym])}/commit/#{sha[0,10]}"
-    `git filter-branch -f --msg-filter 'sed "1s/^/#{prefix} /" && echo && echo #{suffix}' -- HEAD~1..HEAD`
+    `git filter-branch -f --msg-filter 'grep "" - | sed "1s/^/#{prefix} /" && echo && echo #{suffix}' -- HEAD~1..HEAD`
     unless $?.success?
       puts "Failed to modify commit message of #{sha}"
       break