diff --git a/MathKit/MPExpressionLayout.m b/MathKit/MPExpressionLayout.m
index 0905031..a28e17e 100644
--- a/MathKit/MPExpressionLayout.m
+++ b/MathKit/MPExpressionLayout.m
@@ -129,14 +129,13 @@
     if (self.expression.countElements == 0) {
         return NSMakeRect(0, kMPEmptyBoxYOrigin, kMPEmptyBoxWidth, kMPEmptyBoxHeight);
     }
-    CGFloat x = 0, y = 0, width = 0, height = 0;
+    CGRect bounds = NSMakeRect(0, 0, 0, 0);
     for (NSUInteger index = 0; index < self.expression.countElements; index++) {
         NSRect elementBounds = [self boundsOfElementAtIndex:index];
-        width += elementBounds.size.width;
-        height = MAX(height, elementBounds.size.height);
-        y = MIN(y, elementBounds.origin.y);
+        elementBounds.origin.x = bounds.size.width;
+        bounds = NSUnionRect(bounds, elementBounds);
     }
-    return NSMakeRect(x, y, width, height);
+    return bounds;
 }