diff --git a/includes/config.h.in b/includes/config.h.in
index b162ee85..2e52f7dd 100644
--- a/includes/config.h.in
+++ b/includes/config.h.in
@@ -142,12 +142,16 @@
 /* Version number of package */
 #undef VERSION
 
-/* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
-   significant byte first (like Motorola and SPARC, unlike Intel and VAX). */
-#if defined __BIG_ENDIAN__
-# define WORDS_BIGENDIAN 1
-#elif ! defined __LITTLE_ENDIAN__
-# undef WORDS_BIGENDIAN
+/* Define to 1 if on AIX 3.
+   System headers sometimes define this.
+   We just want to avoid a redefinition error message.  */
+#ifndef _ALL_SOURCE
+# undef _ALL_SOURCE
+#endif
+
+/* Enable GNU extensions on systems that have them.  */
+#ifndef _GNU_SOURCE
+# undef _GNU_SOURCE
 #endif
 
 /* Define to 1 if on MINIX. */
@@ -191,41 +195,30 @@
 #undef _POSIX_SOURCE
 
 /* Define for Solaris 2.5.1 so the uint32_t typedef from <sys/synch.h>,
-   <pthread.h>, or <semaphore.h> is not used. If the typedef were allowed, the
+   <pthread.h>, or <semaphore.h> is not used. If the typedef was allowed, the
    #define below would cause a syntax error. */
 #undef _UINT32_T
 
 /* Define for Solaris 2.5.1 so the uint64_t typedef from <sys/synch.h>,
-   <pthread.h>, or <semaphore.h> is not used. If the typedef were allowed, the
+   <pthread.h>, or <semaphore.h> is not used. If the typedef was allowed, the
    #define below would cause a syntax error. */
 #undef _UINT64_T
 
 /* Define for Solaris 2.5.1 so the uint8_t typedef from <sys/synch.h>,
-   <pthread.h>, or <semaphore.h> is not used. If the typedef were allowed, the
+   <pthread.h>, or <semaphore.h> is not used. If the typedef was allowed, the
    #define below would cause a syntax error. */
 #undef _UINT8_T
 
-/* Enable extensions on AIX 3, Interix.  */
-#ifndef _ALL_SOURCE
-# undef _ALL_SOURCE
-#endif
-/* Enable GNU extensions on systems that have them.  */
-#ifndef _GNU_SOURCE
-# undef _GNU_SOURCE
-#endif
-/* Enable threading extensions on Solaris.  */
-#ifndef _POSIX_PTHREAD_SEMANTICS
-# undef _POSIX_PTHREAD_SEMANTICS
-#endif
-/* Enable extensions on HP NonStop.  */
-#ifndef _TANDEM_SOURCE
-# undef _TANDEM_SOURCE
-#endif
-/* Enable general extensions on Solaris.  */
+/* Enable extensions on Solaris.  */
 #ifndef __EXTENSIONS__
 # undef __EXTENSIONS__
 #endif
-
+#ifndef _POSIX_PTHREAD_SEMANTICS
+# undef _POSIX_PTHREAD_SEMANTICS
+#endif
+#ifndef _TANDEM_SOURCE
+# undef _TANDEM_SOURCE
+#endif
 
 /* Define to the type of a signed integer type of width exactly 16 bits if
    such a type exists and the standard includes do not define it. */