diff --git a/slirp/ip_input.c b/slirp/ip_input.c
index 629745f..b046840 100644
--- a/slirp/ip_input.c
+++ b/slirp/ip_input.c
@@ -45,14 +45,19 @@
 #include <slirp.h>
 #include "ip_icmp.h"
 
-int ip_defttl;
-
 #ifdef LOG_ENABLED
 struct ipstat ipstat;
 #endif
 
 struct ipq ipq;
 
+static struct ip *ip_reass(register struct ipasfrag *ip,
+                           register struct ipq *fp);
+static void ip_freef(struct ipq *fp);
+static void ip_enq(register struct ipasfrag *p,
+                   register struct ipasfrag *prev);
+static void ip_deq(register struct ipasfrag *p);
+
 /*
  * IP initialization: fill in IP protocol switch table.
  * All protocols not implemented in kernel go to raw IP protocol handler.
@@ -64,7 +69,6 @@
 	ip_id = tt.tv_sec & 0xffff;
 	udp_init();
 	tcp_init();
-	ip_defttl = IPDEFTTL;
 }
 
 /*
@@ -239,10 +243,8 @@
  * reassembly of this datagram already exists, then it
  * is given as fp; otherwise have to make a chain.
  */
-struct ip *
-ip_reass(ip, fp)
-	register struct ipasfrag *ip;
-	register struct ipq *fp;
+static struct ip *
+ip_reass(register struct ipasfrag *ip, register struct ipq *fp)
 {
 	register struct mbuf *m = dtom(ip);
 	register struct ipasfrag *q;
@@ -398,9 +400,8 @@
  * Free a fragment reassembly header and all
  * associated datagrams.
  */
-void
-ip_freef(fp)
-	struct ipq *fp;
+static void
+ip_freef(struct ipq *fp)
 {
 	register struct ipasfrag *q, *p;
 
@@ -418,9 +419,8 @@
  * Put an ip fragment on a reassembly chain.
  * Like insque, but pointers in middle of structure.
  */
-void
-ip_enq(p, prev)
-	register struct ipasfrag *p, *prev;
+static void
+ip_enq(register struct ipasfrag *p, register struct ipasfrag *prev)
 {
 	DEBUG_CALL("ip_enq");
 	DEBUG_ARG("prev = %lx", (long)prev);
@@ -433,9 +433,8 @@
 /*
  * To ip_enq as remque is to insque.
  */
-void
-ip_deq(p)
-	register struct ipasfrag *p;
+static void
+ip_deq(register struct ipasfrag *p)
 {
 	((struct ipasfrag *)(p->ipf_prev))->ipf_next = p->ipf_next;
 	((struct ipasfrag *)(p->ipf_next))->ipf_prev = p->ipf_prev;