diff --git a/extra/math/geometry/geometry.factor b/extra/math/geometry/geometry.factor
index f70864aba3..d82478dd7f 100644
--- a/extra/math/geometry/geometry.factor
+++ b/extra/math/geometry/geometry.factor
@@ -4,5 +4,8 @@ IN: math.geometry
 GENERIC: width  ( object -- width )
 GENERIC: height ( object -- width )
 
+GENERIC# set-width!  1 ( object width  -- object )
+GENERIC# set-height! 1 ( object height -- object )
+
 GENERIC# set-x! 1 ( object x -- object )
 GENERIC# set-y! 1 ( object y -- object )
\ No newline at end of file
diff --git a/extra/math/geometry/rect/rect.factor b/extra/math/geometry/rect/rect.factor
index d5b83e2715..4503d08a0a 100644
--- a/extra/math/geometry/rect/rect.factor
+++ b/extra/math/geometry/rect/rect.factor
@@ -45,5 +45,8 @@ M: array rect-dim drop { 0 0 } ;
 M: rect width  ( rect -- width  ) dim>> first  ;
 M: rect height ( rect -- height ) dim>> second ;
 
+M: rect set-width!  ( rect width  -- rect ) over dim>> set-first  ;
+M: rect set-height! ( rect height -- rect ) over dim>> set-second ;
+
 M: rect set-x! ( rect x -- rect ) over loc>> set-first  ;
 M: rect set-y! ( rect y -- rect ) over loc>> set-second ;