diff --git a/lisp/play/tetris.el b/lisp/play/tetris.el
index 586d1d5..0f3b758 100644
--- a/lisp/play/tetris.el
+++ b/lisp/play/tetris.el
@@ -265,7 +265,7 @@ each one of its four blocks.")
     (define-key map [left]	'tetris-move-left)
     (define-key map [right]	'tetris-move-right)
     (define-key map [up]	'tetris-rotate-prev)
-    (define-key map [down]	'tetris-rotate-next)
+    (define-key map [down]	'tetris-move-down)
     map))
 
 (defvar tetris-null-map
@@ -524,6 +524,16 @@ Drops the shape one square, testing for collision."
 	(setq tetris-pos-x (1- tetris-pos-x)))
     (tetris-draw-shape)))
 
+(defun tetris-move-down ()
+  "Move the shape one square to the bottom."
+  (interactive)
+  (unless tetris-paused
+    (tetris-erase-shape)
+    (setq tetris-pos-y (1+ tetris-pos-y))
+    (if (tetris-test-shape)
+	(setq tetris-pos-y (1- tetris-pos-y)))
+    (tetris-draw-shape)))
+
 (defun tetris-rotate-prev ()
   "Rotate the shape clockwise."
   (interactive)