diff --git a/include/boost/regex/v5/perl_matcher_non_recursive.hpp b/include/boost/regex/v5/perl_matcher_non_recursive.hpp
index 28d6c462..009788d2 100644
--- a/include/boost/regex/v5/perl_matcher_non_recursive.hpp
+++ b/include/boost/regex/v5/perl_matcher_non_recursive.hpp
@@ -1204,6 +1204,8 @@ bool perl_matcher<BidiIterator, Allocator, traits>::skip_until_paren(int index,
       else if(pstate->type == syntax_element_startmark)
       {
          int idx = static_cast<const re_brace*>(pstate)->index;
+         //if (idx == -5)
+            match_startmark();
          pstate = pstate->next.p;
          skip_until_paren(idx, false);
          continue;