--- a/python-ethtool/etherinfo.h
+++ b/python-ethtool/etherinfo.h
@@ -23,7 +23,7 @@ int get_etherinfo_link(PyEtherInfo *data
 PyObject * get_etherinfo_address(PyEtherInfo *self, nlQuery query);
 
 int open_netlink(PyEtherInfo *);
-struct nl_sock * get_nlc();
+struct nl_sock * get_nlc(void);
 void close_netlink(PyEtherInfo *);
 
 #endif
--- a/python-ethtool/ethtool.c
+++ b/python-ethtool/ethtool.c
@@ -524,7 +524,7 @@ static int send_command(int cmd, const c
 	eval->cmd = cmd;
 
 	/* Open control socket. */
-	fd = socket(AF_INET, SOCK_DGRAM, 0), err;
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
 	if (fd < 0) {
 		PyErr_SetFromErrno(PyExc_OSError);
 		return -1;
--- a/python-ethtool/netlink.c
+++ b/python-ethtool/netlink.c
@@ -85,7 +85,7 @@ int open_netlink(PyEtherInfo *ethi)
  *
  * @returns Returns a pointer to a NETLINK connection libnl functions can use
  */
-struct nl_sock * get_nlc()
+struct nl_sock * get_nlc(void)
 {
 	assert(nlconnection);
 	return nlconnection;
