diff --git a/code/debug-int.lisp b/code/debug-int.lisp
index 244b4f1b8eb9a2e72a4339187d661a4d41393d4e..960fde37a7807259e07a61c1665fa06bf5407f47 100644
--- a/code/debug-int.lisp
+++ b/code/debug-int.lisp
@@ -7,7 +7,7 @@
 ;;; Scott Fahlman or slisp-group@cs.cmu.edu.
 ;;;
 (ext:file-comment
-  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/debug-int.lisp,v 1.50 1992/06/22 13:51:30 wlott Exp $")
+  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/debug-int.lisp,v 1.51 1992/07/09 19:26:13 wlott Exp $")
 ;;;
 ;;; **********************************************************************
 ;;;
@@ -1076,7 +1076,8 @@
 	     (let* ((code-header-len (* (kernel:get-header-data code)
 					vm:word-bytes))
 		    (pc-offset
-		     (- (system:sap-int (alien:slot scp 'unix:sc-pc))
+		     (- (system:sap-int
+			 (vm:sigcontext-program-counter scp))
 			(- (kernel:get-lisp-obj-address code)
 			   vm:other-pointer-type)
 			code-header-len)))
diff --git a/code/signal.lisp b/code/signal.lisp
index aaa08dc11b002af056beb0932e139cb4e5a2cc12..1ba22cb09c0a12e9c0d9ba413493ef682e252c62 100644
--- a/code/signal.lisp
+++ b/code/signal.lisp
@@ -7,11 +7,11 @@
 ;;; Scott Fahlman or slisp-group@cs.cmu.edu.
 ;;;
 (ext:file-comment
-  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/signal.lisp,v 1.16 1992/07/08 17:19:39 ram Exp $")
+  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/signal.lisp,v 1.17 1992/07/09 19:27:05 wlott Exp $")
 ;;;
 ;;; **********************************************************************
 ;;;
-;;; $Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/signal.lisp,v 1.16 1992/07/08 17:19:39 ram Exp $
+;;; $Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/signal.lisp,v 1.17 1992/07/09 19:27:05 wlott Exp $
 ;;;
 ;;; Code for handling UNIX signals.
 ;;; 
@@ -233,7 +233,7 @@
      (system:without-hemlock
       (,function ,(concatenate 'simple-string what " at #x~x.")
 		 (with-alien ((scp (* sigcontext) scp))
-		   (sap-int (slot scp 'sc-pc)))))))
+		   (sap-int (vm:sigcontext-program-counter scp)))))))
 
 (define-signal-handler sigint-handler "Interrupted" break)
 (define-signal-handler sigill-handler "Illegal Instruction")