diff --git a/zebra/ipforward_sysctl.c b/zebra/ipforward_sysctl.c
index 53b6c6f..a8d0d8c 100644
--- a/zebra/ipforward_sysctl.c
+++ b/zebra/ipforward_sysctl.c
@@ -44,7 +44,7 @@
 int
 ipforward ()
 {
-  int len;
+  size_t len;
   int ipforwarding = 0;
 
   len = sizeof ipforwarding;
@@ -59,7 +59,7 @@
 int
 ipforward_on ()
 {
-  int len;
+  size_t len;
   int ipforwarding = 1;
 
   len = sizeof ipforwarding;
@@ -80,7 +80,7 @@
 int
 ipforward_off ()
 {
-  int len;
+  size_t len;
   int ipforwarding = 0;
 
   len = sizeof ipforwarding;
@@ -117,7 +117,7 @@
 int
 ipforward_ipv6 ()
 {
-  int len;
+  size_t len;
   int ip6forwarding = 0;
 
   len = sizeof ip6forwarding;
@@ -138,7 +138,7 @@
 int
 ipforward_ipv6_on ()
 {
-  int len;
+  size_t len;
   int ip6forwarding = 1;
 
   len = sizeof ip6forwarding;
@@ -159,7 +159,7 @@
 int
 ipforward_ipv6_off ()
 {
-  int len;
+  size_t len;
   int ip6forwarding = 0;
 
   len = sizeof ip6forwarding;