diff --git a/week4/README.MD b/week4/README.MD
index be5aeba2ed236a61a7e5a712e954b1f227d9fdf4..356b2725828d17e7929735f6a9a2aae58ca531a6 100644
--- a/week4/README.MD
+++ b/week4/README.MD
@@ -2,7 +2,7 @@
 
 From 6.2, error at different step sizes for Euler integration (both are diverging) and Runge-Kutta with much smaller error.
 
-![](img/6_2_euler_v_runge.png)
+![](img/6_2_euler_v_runge.jpg)
 
 From 6.3, adaptive Runge-Kutta stepper's step size increasing to meet a desired error target. Could have used a more aggressive minimum error term to see the steps oscillate with the derivative instead of just meeting the requirements of the peak derivative.