diff --git a/.prev-version b/.prev-version
index 47b322c9..4d9d11cf 100644
--- a/.prev-version
+++ b/.prev-version
@@ -1 +1 @@
-3.4.1
+3.4.2
diff --git a/NEWS b/NEWS
index 83163f56..44929e35 100644
--- a/NEWS
+++ b/NEWS
@@ -40,7 +40,7 @@ GNU Bison NEWS
   The Java backend no longer emits code and data for parser tracing if the
   %define variable parse.trace is not defined.
 
-* Noteworthy changes in release 3.4.2 (2019-09-08) [stable]
+* Noteworthy changes in release 3.4.2 (2019-09-12) [stable]
 
 ** Bug fixes
 
diff --git a/THANKS b/THANKS
index 4d2b25f7..2cdd9b0b 100644
--- a/THANKS
+++ b/THANKS
@@ -10,6 +10,7 @@ Albert Chin-A-Young       china@thewrittenword.com
 Alexander Belopolsky      alexb@rentec.com
 Alexandre Duret-Lutz      adl@lrde.epita.fr
 Andre da Costa Barros     andre.cbarros@yahoo.com
+Andreas Damm              adamm@onica.com
 Andreas Schwab            schwab@suse.de
 Andrew Suffield           asuffield@users.sourceforge.net
 Angelo Borsotti           angelo.borsotti@gmail.com
diff --git a/data/skeletons/lalr1.cc b/data/skeletons/lalr1.cc
index 13c9bdc4..21e147a1 100644
--- a/data/skeletons/lalr1.cc
+++ b/data/skeletons/lalr1.cc
@@ -354,6 +354,10 @@ m4_define([b4_shared_declarations],
       /// Assignment, needed by push_back by some old implementations.
       /// Moves the contents of that.
       stack_symbol_type& operator= (stack_symbol_type& that);
+
+      /// Assignment, needed by push_back by other implementations.
+      /// Needed by some other old implementations.
+      stack_symbol_type& operator= (const stack_symbol_type& that);
 #endif
     };
 
@@ -657,6 +661,17 @@ m4_if(b4_prefix, [yy], [],
   }
 
 #if YY_CPLUSPLUS < 201103L
+  ]b4_parser_class[::stack_symbol_type&
+  ]b4_parser_class[::stack_symbol_type::operator= (const stack_symbol_type& that)
+  {
+    state = that.state;
+    ]b4_variant_if([b4_symbol_variant([that.type_get ()],
+                                      [value], [copy], [that.value])],
+                   [[value = that.value;]])[]b4_locations_if([
+    location = that.location;])[
+    return *this;
+  }
+
   ]b4_parser_class[::stack_symbol_type&
   ]b4_parser_class[::stack_symbol_type::operator= (stack_symbol_type& that)
   {