--- ./configure.orig	2013-03-02 18:24:29.000000000 +0100
+++ ./configure	2013-03-27 20:43:21.000000000 +0100
@@ -4945,7 +4945,7 @@
 
 
 # Check whether --enable-nfprofile was given.
-if test "${enable_nfprofile+set}" = set; then :
+if test "x${enable_nfprofile}" = xyes; then :
   enableval=$enable_nfprofile;
 	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for rrd_update in -lrrd" >&5
 $as_echo_n "checking for rrd_update in -lrrd... " >&6; }
@@ -5069,7 +5069,7 @@
 
 
 # Check whether --enable-nftrack was given.
-if test "${enable_nftrack+set}" = set; then :
+if test "x${enable_nftrack}" = xyes; then :
   enableval=$enable_nftrack;
 	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for rrd_update in -lrrd" >&5
 $as_echo_n "checking for rrd_update in -lrrd... " >&6; }