--- a/src/runtime/Config.x86_64-linux
+++ b/src/runtime/Config.x86_64-linux
@@ -7,9 +7,24 @@
 # provided with absolutely no warranty. See the COPYING and CREDITS
 # files for more information.
 
-include Config.x86-linux
+ASSEM_SRC = x86-64-assem.S ldso-stubs.S
+ARCH_SRC = x86-64-arch.c
 
-# Until a 64-bit port is written, tell the compiler to use 32-bit mode
+OS_SRC = linux-os.c x86-64-linux-os.c os-common.c
+# The "--Wl,--export-dynamic" flags are here to help people
+# experimenting with callbacks from C to SBCL, by allowing linkage to
+# SBCL src/runtime/*.c symbols from C. Work on this is good, but it's
+# definitely bleeding edge and not particularly stable. In particular,
+# not only are the workarounds for the GC relocating Lisp code and
+# data unstable, but even the basic calling convention might end up
+# being unstable. Unless you want to do some masochistic maintenance
+# work when new releases of SBCL come out, please don't try to build
+# real code on this until a coherent stable interface has been added.
+# (You *are* encouraged to design and implement a coherent stable
+# interface, though.:-| As far as I (WHN 2002-05-19) know, no one is
+# working on one and it would be a nice thing to have.)
+OS_LINK_FLAGS = -Wl,--export-dynamic
+OS_LIBS = -ldl
 
-CFLAGS += -m32
-OS_LINK_FLAGS += -m32
+GC_SRC = gencgc.c
+