diff --git a/lib/librarian/puppet/source/githubtarball/repo.rb b/lib/librarian/puppet/source/githubtarball/repo.rb
index af47fac4..d9e61c7d 100644
--- a/lib/librarian/puppet/source/githubtarball/repo.rb
+++ b/lib/librarian/puppet/source/githubtarball/repo.rb
@@ -25,7 +25,7 @@ def versions
             all_versions = data.map { |r| r['name'].gsub(/^v/, '') }.sort.reverse
 
             all_versions.delete_if do |version|
-              version !~ /\A\d\.\d(\.\d.*)?\z/
+              version !~ /\A\d+\.\d+(\.\d+.*)?\z/
             end
 
             @versions = all_versions.compact