diff --git a/src/buildvm_x86.dasc b/src/buildvm_x86.dasc
index 384af0d2..23a09bd0 100644
--- a/src/buildvm_x86.dasc
+++ b/src/buildvm_x86.dasc
@@ -24,9 +24,9 @@
 |.define KBASEa,	KBASE
 |.define PC,		esi		// Must be C callee-save.
 |.else
-|.define KBASE,		r13d		// Must be C callee-save.
-|.define KBASEa,	r13
-|.define PC,		r12d		// Must be C callee-save.
+|.define KBASE,		r15d		// Must be C callee-save.
+|.define KBASEa,	r15
+|.define PC,		r14d		// Must be C callee-save.
 |.endif
 |.define DISPATCH,	ebx		// Must be C callee-save.
 |