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)
 {
 
diff --git a/lib/ippool.h b/lib/ippool.h
index 53154f2..e3c1c92 100644
--- a/lib/ippool.h
+++ b/lib/ippool.h
@@ -69,7 +69,7 @@
 extern unsigned long int ippool_hash(struct in46_addr *addr);
 
 /* Create new address pool */
-extern int ippool_new(struct ippool_t **this, char *dyn, char *stat,
+extern int ippool_new(struct ippool_t **this, const char *dyn, const char *stat,
 		      int allowdyn, int allowstat, int flags);
 
 /* Delete existing address pool */