Index: head/sys/conf/kern.opts.mk
===================================================================
--- head/sys/conf/kern.opts.mk
+++ head/sys/conf/kern.opts.mk
@@ -45,6 +45,7 @@
 
 __DEFAULT_NO_OPTIONS = \
     EISA \
+    EXTRA_TCP_STACKS \
     NAND \
     OFED
 
Index: head/sys/conf/kern.post.mk
===================================================================
--- head/sys/conf/kern.post.mk
+++ head/sys/conf/kern.post.mk
@@ -23,6 +23,10 @@
 MKMODULESENV+=	WITH_CTF="${WITH_CTF}"
 .endif
 
+.if defined(WITH_EXTRA_TCP_STACKS)
+MKMODULESENV+=	WITH_EXTRA_TCP_STACKS="${WITH_EXTRA_TCP_STACKS}"
+.endif
+
 # Allow overriding the kernel debug directory, so kernel and user debug may be
 # installed in different directories. Setting it to "" restores the historical
 # behavior of installing debug files in the kernel directory.
Index: head/sys/modules/Makefile
===================================================================
--- head/sys/modules/Makefile
+++ head/sys/modules/Makefile
@@ -353,7 +353,7 @@
 	${_syscons} \
 	sysvipc \
 	${_ti} \
-	tcp/fastpath \
+	${_tcp_fastpath} \
 	tests/framework \
 	tests/callout_test \
 	tl \
@@ -436,6 +436,10 @@
 SUBDIR+=	cuse
 .endif
 
+.if ${MK_EXTRA_TCP_STACKS} != "no" || defined(ALL_MODULES)
+_tcp_fastpath=	tcp/fastpath
+.endif
+
 .if (${MK_INET_SUPPORT} != "no" || ${MK_INET6_SUPPORT} != "no") || \
 	defined(ALL_MODULES)
 _carp=		carp