diff --git a/Foundation/_CGGeometry.h b/Foundation/_CGGeometry.h
index 5ea60e41c..48f91807d 100644
--- a/Foundation/_CGGeometry.h
+++ b/Foundation/_CGGeometry.h
@@ -80,6 +80,7 @@ CGGeometry is not a part of Foundation. The reason _CGGeometry.h exists, and is
 
 #define _CGInsetMake(_top, _right, _bottom, _left) { top:(_top), right:(_right), bottom:(_bottom), left:(_left)  }
 #define _CGInsetMakeCopy(anInset) _CGInsetMake(anInset.top, anInset.right, anInset.bottom, anInset.left)
+#define _CGInsetMakeInvertedCopy(anInset) _CGInsetMake(-anInset.top, -anInset.right, -anInset.bottom, -anInset.left)
 #define _CGInsetMakeZero() _CGInsetMake(0, 0, 0, 0)
 #define _CGInsetIsEmpty(anInset) ((anInset).top === 0 && (anInset).right === 0 && (anInset).bottom === 0 && (anInset).left === 0)
 #define _CGInsetEqualToInset(lhsInset, rhsInset) ((lhsInset).top === (rhsInset).top && (lhsInset).right === (rhsInset).right && (lhsInset).bottom === (rhsInset).bottom && (lhsInset).left === (rhsInset).left)
diff --git a/Foundation/_CGGeometry.j b/Foundation/_CGGeometry.j
index bbb116d9b..be7bc79b3 100644
--- a/Foundation/_CGGeometry.j
+++ b/Foundation/_CGGeometry.j
@@ -72,6 +72,7 @@ _function(CGRectContainsPoint(aRect, aPoint))
 _function(CGInsetMake(top, right, bottom, left))
 _function(CGInsetMakeZero())
 _function(CGInsetMakeCopy(anInset))
+_function(CGInsetMakeInvertedCopy(anInset))
 _function(CGInsetIsEmpty(anInset))
 _function(CGInsetEqualToInset(lhsInset, rhsInset))