diff --git a/bootfiles/18e/boot19.lisp b/bootfiles/18e/boot19.lisp
new file mode 100644
index 0000000000000000000000000000000000000000..b307d258fdd7eef78833ae93b63103dc8b44cea1
--- /dev/null
+++ b/bootfiles/18e/boot19.lisp
@@ -0,0 +1,9 @@
+;; For Sparc only, to make these constants available when building
+;; from a release that didn't have these defined.
+
+#+sparc
+(in-package :vm)
+#+sparc
+(defconstant pseudo-atomic-value (ash 1 (1- vm:lowtag-bits)))
+#+sparc
+(defconstant pseudo-atomic-interrupted-value 1)