diff --git a/include/proto/vars.h b/include/proto/vars.h
index e1092c7..4c85825 100644
--- a/include/proto/vars.h
+++ b/include/proto/vars.h
@@ -5,6 +5,7 @@
 
 void vars_init(struct vars *vars, enum vars_scope scope);
 void vars_prune(struct vars *vars, struct stream *strm);
+void vars_prune_per_sess(struct vars *vars);
 int vars_get_by_name(const char *name, size_t len, struct stream *strm, struct sample *smp);
 void vars_set_by_name(const char *name, size_t len, struct stream *strm, struct sample *smp);
 int vars_check_arg(struct arg *arg, char **err);