diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index dc9957b69e0..1a358c3afd4 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -3,6 +3,16 @@
 	Backport from mainline
 	2017-12-27  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/83600
+	* include/bits/regex.h (match_results::end()): Return valid iterator
+	when not ready.
+	* testsuite/28_regex/match_results/ctors/char/default.cc: Check that
+	unready objects are empty and have equal begin and end iterators.
+	* testsuite/28_regex/match_results/ctors/wchar_t/default.cc: Likewise.
+
+	Backport from mainline
+	2017-12-27  Jonathan Wakely  <jwakely@redhat.com>
+
 	PR libstdc++/83598
 	* include/bits/regex.h (basic_regex): Don't modify flags passed to
 	constructors.
diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h
index 2fecffed336..14a1ae6f61d 100644
--- a/libstdc++-v3/include/bits/regex.h
+++ b/libstdc++-v3/include/bits/regex.h
@@ -1751,7 +1751,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
        */
       const_iterator
       end() const
-      { return _Base_type::end() - 3; }
+      { return _Base_type::end() - (empty() ? 0 : 3); }
 
       /**
        * @brief Gets an iterator to one-past-the-end of the collection.
diff --git a/libstdc++-v3/testsuite/28_regex/match_results/ctors/char/default.cc b/libstdc++-v3/testsuite/28_regex/match_results/ctors/char/default.cc
index a6d1375df9e..c2177580ebb 100644
--- a/libstdc++-v3/testsuite/28_regex/match_results/ctors/char/default.cc
+++ b/libstdc++-v3/testsuite/28_regex/match_results/ctors/char/default.cc
@@ -30,6 +30,8 @@ void test01()
   std::cmatch cm;
   VERIFY( cm.size() == 0 );
   VERIFY( !cm.ready() );
+  VERIFY( cm.empty() );
+  VERIFY( cm.begin() == cm.end() ); // PR libstdc++/83600
 }
 
 void test02()
@@ -37,6 +39,8 @@ void test02()
   std::smatch sm;
   VERIFY( sm.size() == 0 );
   VERIFY( !sm.ready() );
+  VERIFY( sm.empty() );
+  VERIFY( sm.begin() == sm.end() ); // PR libstdc++/83600
 }
 
 int
diff --git a/libstdc++-v3/testsuite/28_regex/match_results/ctors/wchar_t/default.cc b/libstdc++-v3/testsuite/28_regex/match_results/ctors/wchar_t/default.cc
index f1d0a3f1191..22e25e13f39 100644
--- a/libstdc++-v3/testsuite/28_regex/match_results/ctors/wchar_t/default.cc
+++ b/libstdc++-v3/testsuite/28_regex/match_results/ctors/wchar_t/default.cc
@@ -30,6 +30,8 @@ void test01()
   std::wcmatch cm;
   VERIFY( cm.size() == 0 );
   VERIFY( !cm.ready() );
+  VERIFY( cm.empty() );
+  VERIFY( cm.begin() == cm.end() ); // PR libstdc++/83600
 }
 
 void test02()
@@ -37,6 +39,8 @@ void test02()
   std::wsmatch sm;
   VERIFY( sm.size() == 0 );
   VERIFY( !sm.ready() );
+  VERIFY( sm.empty() );
+  VERIFY( sm.begin() == sm.end() ); // PR libstdc++/83600
 }
 
 int