diff --git a/Readme.md b/Readme.md
index 2d49bf6..0368a75 100644
--- a/Readme.md
+++ b/Readme.md
@@ -18,7 +18,7 @@ $$\frac{\partial^2 T}{\partial x^2}+ \frac{\partial^2 T}{\partial y^2}=0$$
 
 the problem is defined by the next geometry considerations:
 
-![](physicalproblem.png)
+![](physicalproblem.PNG)
 
 The resulting contour of temperature, solving using finite diferences, is shown next: