diff --git a/nt/ChangeLog b/nt/ChangeLog
index 6f208f2a18f..f851004f605 100644
--- a/nt/ChangeLog
+++ b/nt/ChangeLog
@@ -1,9 +1,7 @@
 2013-03-26  Eli Zaretskii  <eliz@gnu.org>
 
 	* inc/ms-w32.h (USE_NO_MINGW_SETJMP_TWO_ARGS): Don't define.
-
-	* config.nt (HAVE__SETJMP) [!_W64]: Don't define for MinGW64, as
-	its _setjmp accepts 2 arguments.
+	(HAVE__SETJMP) [_W64]: Undefine for MinGW64.
 
 	* addsection.c (_ANONYMOUS_UNION, _ANONYMOUS_STRUCT): Do not
 	define for MinGW64.
diff --git a/nt/config.nt b/nt/config.nt
index 4f151fcad20..3d606258fc0 100644
--- a/nt/config.nt
+++ b/nt/config.nt
@@ -1143,12 +1143,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 /* Define to 1 if you have the `_ftime' function. */
 #undef HAVE__FTIME
 
-/* Define to 1 if _setjmp and _longjmp work.  MinGW64 uses a
-   2-argument _setjmp, and setjmp is a macro defined to supply the 2nd
-   arg correctly, so don't use _setjmp directly in that case.  */
-#ifndef _W64
+/* Define to 1 if _setjmp and _longjmp work.  */
 #define HAVE__SETJMP 1
-#endif
 
 /* Define to 1 if you have the `__builtin_unwind_init' function. */
 #undef HAVE___BUILTIN_UNWIND_INIT
diff --git a/nt/inc/ms-w32.h b/nt/inc/ms-w32.h
index fd18e8fd1da..a2111da6f3e 100644
--- a/nt/inc/ms-w32.h
+++ b/nt/inc/ms-w32.h
@@ -161,6 +161,10 @@ extern char *getenv ();
 /* Make sure 'struct timespec' and 'struct timezone' are defined.  */
 #include <sys/types.h>
 #include <time.h>
+/* MinGW64 uses a 2-argument _setjmp, and setjmp is a macro defined to
+   supply the 2nd arg correctly, so don't use _setjmp directly in that
+   case. */
+#undef HAVE__SETJMP
 #endif
 
 #ifdef _MSC_VER