diff --git a/include/boost/regex/config.hpp b/include/boost/regex/config.hpp
index fa102783..107824d8 100644
--- a/include/boost/regex/config.hpp
+++ b/include/boost/regex/config.hpp
@@ -125,8 +125,10 @@
 // If there isn't good enough wide character support then there will
 // be no wide character regular expressions:
 //
-#if (defined(BOOST_NO_CWCHAR) || defined(BOOST_NO_CWCTYPE) || defined(BOOST_NO_STD_WSTRING)) && !defined(BOOST_NO_WREGEX)
-#  define BOOST_NO_WREGEX
+#if (defined(BOOST_NO_CWCHAR) || defined(BOOST_NO_CWCTYPE) || defined(BOOST_NO_STD_WSTRING))
+#  if !defined(BOOST_NO_WREGEX)
+#     define BOOST_NO_WREGEX
+#  endif
 #else
 #  if defined(__sgi) && defined(__SGI_STL_PORT)
       // STLPort on IRIX is misconfigured: <cwctype> does not compile
@@ -645,3 +647,4 @@ inline void pointer_construct(T* p, const T& t)
 
 
 
+
diff --git a/include/boost/regex/v3/regex_compile.hpp b/include/boost/regex/v3/regex_compile.hpp
index 505353af..5059b5f9 100644
--- a/include/boost/regex/v3/regex_compile.hpp
+++ b/include/boost/regex/v3/regex_compile.hpp
@@ -1990,6 +1990,8 @@ unsigned int BOOST_REGEX_CALL reg_expression<charT, traits, Allocator>::probe_re
    {
    case re_detail::syntax_element_startmark:
    case re_detail::syntax_element_endmark:
+      if(static_cast<const re_detail::re_brace*>(dat)->index == -2)
+         return regbase::restart_any;
       return probe_restart(dat->next.p);
    case re_detail::syntax_element_start_line:
       return regbase::restart_line;
@@ -2018,7 +2020,7 @@ unsigned int BOOST_REGEX_CALL reg_expression<charT, traits, Allocator>::fixup_le
          if((leading_lit) && (static_cast<re_detail::re_literal*>(dat)->length > 2))
          {
             // we can do a literal search for the leading literal string
-            // using Knuth-Morris-Pratt (or whatever), and only then check for 
+            // using Knuth-Morris-Pratt (or whatever), and only then check for
             // matches.  We need a decent length string though to make it
             // worth while.
             _leading_string = reinterpret_cast<charT*>(reinterpret_cast<char*>(dat) + sizeof(re_detail::re_literal));
@@ -2070,6 +2072,10 @@ unsigned int BOOST_REGEX_CALL reg_expression<charT, traits, Allocator>::fixup_le
             return len;
          }
          return len;
+      case re_detail::syntax_element_startmark:
+         if(static_cast<const re_detail::re_brace*>(dat)->index == -2)
+            return 0;
+         // fall through:
       default:
          break;
       }
diff --git a/include/boost/regex/v3/regex_match.hpp b/include/boost/regex/v3/regex_match.hpp
index 7576240e..ad5362c4 100644
--- a/include/boost/regex/v3/regex_match.hpp
+++ b/include/boost/regex/v3/regex_match.hpp
@@ -56,8 +56,10 @@ inline int string_compare(const std::basic_string<C,T,A>& s, const C* p)
 { return s.compare(p); }
 inline int string_compare(const std::string& s, const char* p)
 { return std::strcmp(s.c_str(), p); }
+# ifndef BOOST_NO_WREGEX
 inline int string_compare(const std::wstring& s, const wchar_t* p)
 { return std::wcscmp(s.c_str(), p); }
+# endif
 # define STR_COMP(s,p) string_compare(s,p)
 #endif
 
@@ -753,6 +755,15 @@ bool query_match_aux(iterator first,
                   start_loop[cur_acc] = first;
                   continue;
                }
+               else if((unsigned int)accumulators[cur_acc] < static_cast<const re_repeat*>(ptr)->min)
+               {
+                  // the repeat was null, and we haven't gone round min times yet,
+                  // since all subsequent repeats will be null as well, just update
+                  // our repeat count and skip out.
+                  accumulators[cur_acc] = static_cast<const re_repeat*>(ptr)->min;
+                  ptr = static_cast<const re_repeat*>(ptr)->alt.p;
+                  continue;
+               }
                goto failure;
             }
             // see if we can skip the repeat:
@@ -809,6 +820,15 @@ bool query_match_aux(iterator first,
             start_loop[cur_acc] = first;
             continue;
          }
+         else if((first == start_loop[cur_acc]) && accumulators[cur_acc] && ((unsigned int)accumulators[cur_acc] < static_cast<const re_repeat*>(ptr)->min))
+         {
+            // the repeat was null, and we haven't gone round min times yet,
+            // since all subsequent repeats will be null as well, just update
+            // our repeat count and skip out.
+            accumulators[cur_acc] = static_cast<const re_repeat*>(ptr)->min;
+            ptr = static_cast<const re_repeat*>(ptr)->alt.p;
+            continue;
+         }
 
          // if we get here then neither option is allowed so fail:
          goto failure;
@@ -826,7 +846,7 @@ bool query_match_aux(iterator first,
             if(flags & match_not_eob)
                goto failure;
             iterator p(first);
-            while((p != last) && traits_inst.is_separator(traits_inst.translate(*first, icase)))++p;
+            while((p != last) && traits_inst.is_separator(traits_inst.translate(*p, icase)))++p;
             if(p != last)
                goto failure;
             ptr = ptr->next.p;
@@ -958,6 +978,12 @@ bool query_match_aux(iterator first,
             goto failure;
          ptr = ptr->next.p;
          continue;
+      case syntax_element_backref:
+         if(temp_match[static_cast<const re_brace*>(ptr)->index].first
+               != temp_match[static_cast<const re_brace*>(ptr)->index].second)
+               goto failure;
+         ptr = ptr->next.p;
+         continue;
       default:
          goto failure;
       }