diff --git a/libstdc++-v3/include/bits/regex_error.h b/libstdc++-v3/include/bits/regex_error.h
index d3713fa5f47..722ce26cda3 100644
--- a/libstdc++-v3/include/bits/regex_error.h
+++ b/libstdc++-v3/include/bits/regex_error.h
@@ -61,6 +61,7 @@ namespace regex_constants
       _S_error_badrepeat,
       _S_error_complexity,
       _S_error_stack,
+      _S_null
     };
 
   /** The expression contained an invalid collating element name. */
diff --git a/libstdc++-v3/include/bits/regex_scanner.tcc b/libstdc++-v3/include/bits/regex_scanner.tcc
index b2b709ce3cb..d81627dc3e9 100644
--- a/libstdc++-v3/include/bits/regex_scanner.tcc
+++ b/libstdc++-v3/include/bits/regex_scanner.tcc
@@ -175,6 +175,16 @@ namespace __detail
 	  _M_state = _S_state_in_brace;
 	  _M_token = _S_token_interval_begin;
 	}
+      else if (__builtin_expect(__c == _CharT(0), false))
+	{
+	  if (!_M_is_ecma())
+	    {
+	      __throw_regex_error(regex_constants::_S_null,
+		  "Unexpected null character in regular expression");
+	    }
+	  _M_token = _S_token_ord_char;
+	  _M_value.assign(1, __c);
+	}
       else if (__c != ']' && __c != '}')
 	{
 	  auto __it = _M_token_tbl;
diff --git a/libstdc++-v3/testsuite/28_regex/basic_regex/84110.cc b/libstdc++-v3/testsuite/28_regex/basic_regex/84110.cc
new file mode 100644
index 00000000000..b9971dcaac5
--- /dev/null
+++ b/libstdc++-v3/testsuite/28_regex/basic_regex/84110.cc
@@ -0,0 +1,39 @@
+// { dg-do run { target c++11 } }
+#include <regex>
+#include <string>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  const std::string s(1ul, '\0');
+  std::regex re(s);
+  VERIFY( std::regex_match(s, re) ); // PR libstdc++/84110
+
+#if __cpp_exceptions
+  using namespace std::regex_constants;
+  for (auto syn : {basic, extended, awk, grep, egrep})
+  {
+    try
+    {
+      std::regex{s, syn}; // '\0' is not valid for other grammars
+      VERIFY( false );
+    }
+    catch (const std::regex_error&)
+    {
+    }
+  }
+#endif
+}
+
+void test02()
+{
+  const std::string s("uh-\0h", 5);
+  std::regex re(s);
+  VERIFY( std::regex_match(s, re) );
+}
+
+int main()
+{
+  test01();
+  test02();
+}