diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c
index 422254d..c77669a 100644
--- a/networking/udhcp/d6_dhcpc.c
+++ b/networking/udhcp/d6_dhcpc.c
@@ -930,6 +930,8 @@
 	int retval;
 	fd_set rfds;
 
+	setup_common_bufsiz();
+
 	/* Default options */
 	IF_FEATURE_UDHCP_PORT(SERVER_PORT6 = 547;)
 	IF_FEATURE_UDHCP_PORT(CLIENT_PORT6 = 546;)
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 660b943..8f5a03f 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -1268,6 +1268,8 @@
 	int retval;
 	fd_set rfds;
 
+	setup_common_bufsiz();
+
 	/* Default options */
 	IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
 	IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index 2671ea3..e93a9f1 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -310,10 +310,10 @@
 	unsigned arpping_ms;
 	IF_FEATURE_UDHCP_PORT(char *str_P;)
 
-#if ENABLE_FEATURE_UDHCP_PORT
-	SERVER_PORT = 67;
-	CLIENT_PORT = 68;
-#endif
+	setup_common_bufsiz();
+
+	IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
+	IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
 
 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
 	opt_complementary = "vv";