diff --git a/lib/ippool.c b/lib/ippool.c
index c3eb267..3ca1b86 100644
--- a/lib/ippool.c
+++ b/lib/ippool.c
@@ -186,7 +186,7 @@
 }
 
 /* Create new address pool */
-int ippool_new(struct ippool_t **this, char *dyn, char *stat,
+int ippool_new(struct ippool_t **this, const char *dyn, const char *stat,
 	       int allowdyn, int allowstat, int flags)
 {