diff --git a/matlab/+gtsam/covarianceEllipse.m b/matlab/+gtsam/covarianceEllipse.m
index 387d7cd12..cdc239bb2 100644
--- a/matlab/+gtsam/covarianceEllipse.m
+++ b/matlab/+gtsam/covarianceEllipse.m
@@ -1,4 +1,4 @@
-function covarianceEllipse(x,P,color, k)
+function h = covarianceEllipse(x,P,color, k)
 % covarianceEllipse plots a Gaussian as an uncertainty ellipse
 % Based on Maybeck Vol 1, page 366
 % k=2.296 corresponds to 1 std, 68.26% of all probability
@@ -13,7 +13,7 @@ s1 = s(1,1);
 s2 = s(2,2);
 if nargin<4, k = 2.296; end;
 [ex,ey] = ellipse( sqrt(s1*k)*e(:,1), sqrt(s2*k)*e(:,2), x(1:2) );
-line(ex,ey,'color',color);
+h = line(ex,ey,'color',color);
 
     function [x,y] = ellipse(a,b,c);
         % ellipse: return the x and y coordinates for an ellipse