--- a/configure.old	2010-10-18 15:05:02.000000000 +0200
+++ b/configure	2010-10-18 15:05:31.000000000 +0200
@@ -5516,12 +5516,12 @@
 
 
 if test "x$x_includes" != "x"; then
-  CFLAGS="-I $x_includes"
-else
-  CFLAGS=""
-fi
-LDFLAGS="-L/usr/local/lib -L$x_libraries -L$libdir"
-CXXFLAGS="$CFLAGS -Wall"
+  CFLAGS="${CFLAGS} -I $x_includes"
+else
+  CFLAGS="${CFLAGS}"
+fi
+LDFLAGS="${LDFLAGS} -L/usr/local/lib -L$x_libraries -L$libdir"
+CXXFLAGS="${CXXFLAGS} -Wall"
 
 
 echo "$as_me:$LINENO: checking for main in -lXmu" >&5