Index: libguile/guile-snarf-docs.in
===================================================================
--- libguile/guile-snarf-docs.in.orig	2010-12-13 19:24:40.000000000 +0200
+++ libguile/guile-snarf-docs.in	2011-09-27 19:41:26.488724499 +0200
@@ -23,4 +23,4 @@ bindir=`dirname $0`
 ## Let the user override the preprocessor autoconf found.
 test -n "${CPP+set}" || CPP="@CPP@"
 
-${CPP} -DSCM_MAGIC_SNARF_DOCS "$@"
+${CPP} -P -DSCM_MAGIC_SNARF_DOCS "$@"