diff --git a/rtnl.c b/rtnl.c
index 59ed0ec..d9c76d7 100644
--- a/rtnl.c
+++ b/rtnl.c
@@ -87,7 +87,7 @@ static void rtnl_get_ts_device_callback(void *ctx, int linkup, int ts_index)
 	*dst = ts_index;
 }
 
-int rtnl_get_ts_device(char *device, char *ts_device)
+int rtnl_get_ts_device(const char *device, char *ts_device)
 {
 	int err, fd;
 	int ts_index = -1;
@@ -112,7 +112,7 @@ no_info:
 	return err;
 }
 
-int rtnl_link_query(int fd, char *device)
+int rtnl_link_query(int fd, const char *device)
 {
 	struct sockaddr_nl sa;
 	struct msghdr msg;
@@ -227,7 +227,7 @@ static int rtnl_linkinfo_parse(int master_index, struct rtattr *rta)
 	return index;
 }
 
-int rtnl_link_status(int fd, char *device, rtnl_callback cb, void *ctx)
+int rtnl_link_status(int fd, const char *device, rtnl_callback cb, void *ctx)
 {
 	struct rtattr *tb[IFLA_MAX+1];
 	struct ifinfomsg *info = NULL;
diff --git a/rtnl.h b/rtnl.h
index f877cd2..c5ea979 100644
--- a/rtnl.h
+++ b/rtnl.h
@@ -37,7 +37,7 @@ int rtnl_close(int fd);
  *                  at least IF_NAMESIZE bytes long.
  * @return          Zero on success, or -1 on error.
  */
-int rtnl_get_ts_device(char *device, char *ts_device);
+int rtnl_get_ts_device(const char *device, char *ts_device);
 
 /**
  * Request the link status from the kernel.
@@ -45,7 +45,7 @@ int rtnl_get_ts_device(char *device, char *ts_device);
  * @param device Interface name. Request all iface's status if set NULL.
  * @return       Zero on success, non-zero otherwise.
  */
-int rtnl_link_query(int fd, char *device);
+int rtnl_link_query(int fd, const char *device);
 
 /**
  * Read kernel messages looking for a link up/down events.
@@ -55,7 +55,7 @@ int rtnl_link_query(int fd, char *device);
  * @param ctx    Private context passed to the callback.
  * @return       Zero on success, non-zero otherwise.
  */
-int rtnl_link_status(int fd, char *device, rtnl_callback cb, void *ctx);
+int rtnl_link_status(int fd, const char *device, rtnl_callback cb, void *ctx);
 
 /**
  * Open a RT netlink socket for monitoring link state.