diff --git a/Makefile b/Makefile
index 18c5a6b..2e774df 100644
--- a/Makefile
+++ b/Makefile
@@ -113,6 +113,9 @@
 # Always enable Realtek NICs for now.
 CONFIG_NICREALTEK ?= yes
 
+# Disable National Semiconductor NICs until support is complete and tested.
+CONFIG_NICNATSEMI ?= no
+
 # Always enable Bus Pirate SPI for now.
 CONFIG_BUSPIRATE_SPI ?= yes
 
@@ -192,6 +195,12 @@
 NEED_PCI := yes
 endif
 
+ifeq ($(CONFIG_NICNATSEMI), yes)
+FEATURE_CFLAGS += -D'CONFIG_NICNATSEMI=1'
+PROGRAMMER_OBJS += nicnatsemi.o
+NEED_PCI := yes
+endif
+
 ifeq ($(CONFIG_BUSPIRATE_SPI), yes)
 FEATURE_CFLAGS += -D'CONFIG_BUSPIRATE_SPI=1'
 PROGRAMMER_OBJS += buspirate_spi.o