diff --git a/tool/release.rb b/tool/release.rb
index 902ea1cb653d..467266afb5b0 100644
--- a/tool/release.rb
+++ b/tool/release.rb
@@ -304,7 +304,7 @@ def unreleased_pull_requests
   end
 
   def released_pull_requests
-    commits = `git log --oneline --grep "^Merge pull request #" #{@previous_release_tag}..#{@previous_stable_branch}`.split("\n")
+    commits = `git log --oneline --grep "^Merge pull request #" #{@previous_release_tag}..#{@stable_branch}`.split("\n")
     commits.filter_map do |commit|
       match = commit.match(/Merge pull request #(\d+) from /)
       match[1].to_i if match