$OpenBSD$
--- configure.orig	Thu Feb  5 23:42:10 2009
+++ configure	Thu Feb  5 23:44:38 2009
@@ -21968,7 +21968,7 @@ else
         ODE_PRECISION=-DdSINGLE
 fi
 
-CPPFLAGS+=" $ODE_PRECISION"
+CPPFLAGS="$CPPFLAGS $ODE_PRECISION"