diff --git a/libnm-core/nm-setting-ip-config.c b/libnm-core/nm-setting-ip-config.c
index 43a2dc3fdd..9e3a9fb14c 100644
--- a/libnm-core/nm-setting-ip-config.c
+++ b/libnm-core/nm-setting-ip-config.c
@@ -63,6 +63,19 @@ const NMUtilsDNSOptionDesc _nm_utils_dns_option_descs[] = {
 	{ NULL,                                        FALSE,   FALSE }
 };
 
+static int
+_addr_size (int family)
+{
+	switch (family) {
+	case AF_INET:
+		return sizeof (in_addr_t);
+	case AF_INET6:
+		return sizeof (struct in6_addr);
+	default:
+		g_return_val_if_reached (0);
+	}
+}
+
 static char *
 canonicalize_ip (int family, const char *ip, gboolean null_any)
 {
@@ -77,9 +90,7 @@ canonicalize_ip (int family, const char *ip, gboolean null_any)
 	g_return_val_if_fail (ret == 1, NULL);
 
 	if (null_any) {
-		int addrlen = (family == AF_INET ? sizeof (struct in_addr) : sizeof (struct in6_addr));
-
-		if (!memcmp (addr_bytes, &in6addr_any, addrlen))
+		if (!memcmp (addr_bytes, &in6addr_any, _addr_size (family)))
 			return NULL;
 	}
 
@@ -101,9 +112,7 @@ canonicalize_ip_binary (int family, gconstpointer ip, gboolean null_any)
 		g_return_val_if_reached (NULL);
 	}
 	if (null_any) {
-		int addrlen = (family == AF_INET ? sizeof (struct in_addr) : sizeof (struct in6_addr));
-
-		if (!memcmp (ip, &in6addr_any, addrlen))
+		if (!memcmp (ip, &in6addr_any, _addr_size (family)))
 			return NULL;
 	}
 	return g_strdup (inet_ntop (family, ip, string, sizeof (string)));
@@ -956,8 +965,7 @@ nm_ip_route_get_next_hop_binary (NMIPRoute *route,
 		inet_pton (route->family, route->next_hop, next_hop);
 		return TRUE;
 	} else {
-		memset (next_hop, 0,
-		        route->family == AF_INET ? sizeof (struct in_addr) : sizeof (struct in6_addr));
+		memset (next_hop, 0, _addr_size (route->family));
 		return FALSE;
 	}
 }