diff --git a/filter/filter.c b/filter/filter.c
index 98df7bd0..77378178 100644
--- a/filter/filter.c
+++ b/filter/filter.c
@@ -680,7 +680,7 @@ filter_same(const struct filter *new, const struct filter *old)
  * filter_commit - do filter comparisons on all the named functions and filters
  */
 void
-filter_commit(const struct config *new, const struct config *old)
+filter_commit(struct config *new, struct config *old)
 {
   if (!old)
     return;
diff --git a/filter/filter.h b/filter/filter.h
index d919cc74..36b63e7c 100644
--- a/filter/filter.h
+++ b/filter/filter.h
@@ -62,7 +62,7 @@ const char *filter_name(const struct filter *filter);
 int filter_same(const struct filter *new, const struct filter *old);
 int f_same(const struct f_line *f1, const struct f_line *f2);
 
-void filter_commit(const struct config *new, const struct config *old);
+void filter_commit(struct config *new, struct config *old);
 
 #define FILTER_ACCEPT NULL
 #define FILTER_REJECT ((void *) 1)