diff --git a/src/bootfiles/20f/boot-20f-cross-x86.lisp b/src/bootfiles/20f/boot-20f-cross-x86.lisp
new file mode 100644
index 0000000000000000000000000000000000000000..d1f33670b7b3375449ffc1ff7099101a10f167bc
--- /dev/null
+++ b/src/bootfiles/20f/boot-20f-cross-x86.lisp
@@ -0,0 +1,9 @@
+;;; Cross-compile script to update extern-alien-name for
+;;; darwin/x86. This makes extern-alien-name on darwin/x86 match
+;;; darwin/ppc, where an underscore is prepended.
+;;;
+;;; A cross-compile might not truly be necessary, but this is known to
+;;; work.
+
+#+(and darwin x86)
+(load "target:tools/cross-scripts/cross-x86-x86.lisp")