diff --git a/sys/conf/Makefile.amd64 b/sys/conf/Makefile.amd64
index b83d935745b6..8887992534d2 100644
--- a/sys/conf/Makefile.amd64
+++ b/sys/conf/Makefile.amd64
@@ -31,6 +31,11 @@ S=	../../..
 .endif
 .include "$S/conf/kern.pre.mk"
 
+DDB_ENABLED!=	grep DDB opt_ddb.h
+.if ${DDB_ENABLED} != ""
+CFLAGS+=	-fno-omit-frame-pointer
+.endif
+
 MKMODULESENV+= MACHINE=amd64
 
 %BEFORE_DEPEND
diff --git a/sys/conf/files.amd64 b/sys/conf/files.amd64
index 650bac4f4dea..8e1c68dbce52 100644
--- a/sys/conf/files.amd64
+++ b/sys/conf/files.amd64
@@ -44,10 +44,14 @@ dev/syscons/syscons.c		optional	sc
 dev/syscons/sysmouse.c		optional	sc
 isa/atkbd_isa.c			optional	atkbd
 
+amd64/amd64/amd64-gdbstub.c	optional	ddb
 amd64/amd64/autoconf.c		standard
 amd64/amd64/busdma_machdep.c	standard
 amd64/amd64/cpu_switch.S	standard
 amd64/amd64/critical.c		standard
+amd64/amd64/db_disasm.c		optional	ddb
+amd64/amd64/db_interface.c	optional	ddb
+amd64/amd64/db_trace.c		optional	ddb
 amd64/amd64/dump_machdep.c	standard
 amd64/amd64/elf_machdep.c	standard
 amd64/amd64/exception.S		standard