diff --git a/src/tscore/Regex.cc b/src/tscore/Regex.cc
index 9d93c8d5247..ea801166437 100644
--- a/src/tscore/Regex.cc
+++ b/src/tscore/Regex.cc
@@ -111,7 +111,7 @@ Regex::get_capture_count()
 bool
 Regex::exec(std::string_view const &str)
 {
-  std::array<int, DEFAULT_GROUP_COUNT * 3> ovector;
+  std::array<int, DEFAULT_GROUP_COUNT * 3> ovector = {0};
   return this->exec(str, ovector.data(), ovector.size());
 }