diff --git a/src/core/dns_cache.c b/src/core/dns_cache.c
index d9fc6a21cca..e60be2cd05e 100644
--- a/src/core/dns_cache.c
+++ b/src/core/dns_cache.c
@@ -3739,7 +3739,7 @@ int dns_cache_print_entry(rpc_t* rpc, void* ctx, struct dns_hash_entry* e)
 				}
 				break;
 			case T_NAPTR:
-				if(rpc->struct_add(sh, "ds",
+				if(rpc->struct_add(sh, "dd",
 						"rr_order", ((struct naptr_rdata*)(rr->rdata))->order,
 						"rr_preference", ((struct naptr_rdata*)(rr->rdata))->pref)
 							<0) {