$OpenBSD$
--- configure.orig	Tue Feb 24 20:49:53 2009
+++ configure	Tue Feb 24 20:50:56 2009
@@ -21968,7 +21968,7 @@ else
         ODE_PRECISION=-DdSINGLE
 fi
 
-CPPFLAGS+=" $ODE_PRECISION"
+CPPFLAGS="$CPPFLAGS $ODE_PRECISION"