diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index ea4affe77c4..34afcee4b1c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2012-10-03  Martin Rudalics  <rudalics@gmx.at>
+
+	* emacs-lisp/debug.el (debug): When quitting the debugger window
+	restore current buffer (Bug#12502).
+
 2012-10-02  Chong Yidong  <cyd@gnu.org>
 
 	* progmodes/hideif.el (hif-lookup, hif-defined): Handle
diff --git a/lisp/emacs-lisp/debug.el b/lisp/emacs-lisp/debug.el
index 6fd52d67b90..6b308119abb 100644
--- a/lisp/emacs-lisp/debug.el
+++ b/lisp/emacs-lisp/debug.el
@@ -273,7 +273,9 @@ first will be printed into the backtrace buffer."
 	    (setq debugger-previous-window-height
 		  (window-total-size debugger-window))
 	    ;; Unshow debugger-buffer.
-	    (quit-restore-window debugger-window debugger-bury-or-kill))
+	    (quit-restore-window debugger-window debugger-bury-or-kill)
+	    ;; Restore current buffer (Bug#12502).
+	    (set-buffer debugger-old-buffer))
           ;; Restore previous state of debugger-buffer in case we were
           ;; in a recursive invocation of the debugger, otherwise just
           ;; erase the buffer and put it into fundamental mode.