diff --git a/include/boost/detail/limits.hpp b/include/boost/detail/limits.hpp
index 91d4d669..6369b2c9 100644
--- a/include/boost/detail/limits.hpp
+++ b/include/boost/detail/limits.hpp
@@ -49,9 +49,9 @@
 
 // The macros are not named appropriately.  We don't care about integer
 // bit layout, but about floating-point NaN (etc.) bit patterns.
-#if defined(__sparc) || defined(__sparc__) || defined(__powerpc__) || defined(__ppc__) || defined(__hppa) || defined(_MIPSEB)
+#if defined(__sparc) || defined(__sparc__) || defined(__powerpc__) || defined(__ppc__) || defined(__hppa) || defined(_MIPSEB) || defined(_POWER)
 #define BOOST_BIG_ENDIAN
-#elif defined(__i386__)
+#elif defined(__i386__) || defined(__alpha__)
 #define BOOST_LITTLE_ENDIAN
 #else
 #error The file boost/detail/limits.hpp needs to be set up for your CPU type.