--- a/pjlib/include/pj/config.h	2014-10-15 09:56:34.510724006 -0600
+++ a/pjlib/include/pj/config.h	2014-10-19 13:46:46.071057753 -0600
@@ -238,14 +238,22 @@ 
 #elif defined (PJ_M_ARMV4) || defined(ARM) || defined(_ARM_) ||  \
 	defined(ARMV4) || defined(__arm__)
     /*
-     * ARM, bi-endian, so raise error if endianness is not configured
+     * ARM, bi-endian, so raise error if endianness is not configured or detected
      */
 #   undef PJ_M_ARMV4
 #   define PJ_M_ARMV4		1
 #   define PJ_M_NAME		"armv4"
 #   define PJ_HAS_PENTIUM	0
 #   if !PJ_IS_LITTLE_ENDIAN && !PJ_IS_BIG_ENDIAN
-#   	error Endianness must be declared for this processor
+#      if (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+#         define PJ_IS_LITTLE_ENDIAN	1
+#         define PJ_IS_BIG_ENDIAN	0
+#      elif (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#         define PJ_IS_LITTLE_ENDIAN	0
+#         define PJ_IS_BIG_ENDIAN	1
+#      else
+#         error Endianness must be declared for this processor
+#      endif
 #   endif
 
 #elif defined (PJ_M_POWERPC) || defined(__powerpc) || defined(__powerpc__) || \