--- gr_boost.m4_orig	Mon Aug 25 15:20:23 2008
+++ gr_boost.m4	Mon Aug 25 15:20:49 2008
@@ -91,11 +91,11 @@
 
 	pattern="/usr/local/include/boost-*"
 	boost_last_match "$pattern" $pattern
 	#echo "LM(2)='$LM'"
 
-        OLD_CPPFLAGS=$CPP_FLAGS
+        OLD_CPPFLAGS=$CPPFLAGS
         CPPFLAGS="$CPPFLAGS -I$LM"
         AC_CHECK_HEADER([boost/shared_ptr.hpp],
           [BOOST_CFLAGS="-I$LM"],
           [AC_MSG_ERROR(
             [Failed to locate boost/shared_ptr.hpp.