diff --git a/pkgs/development/libraries/box2d/default.nix b/pkgs/development/libraries/box2d/default.nix
index 47a1c0917f0..17830b053ac 100644
--- a/pkgs/development/libraries/box2d/default.nix
+++ b/pkgs/development/libraries/box2d/default.nix
@@ -7,10 +7,10 @@ stdenv.mkDerivation rec {
 
   src = fetchurl {
     url = "https://github.com/erincatto/Box2D/archive/v${version}.tar.gz";
-    sha256 = "0llpcifl8zbjbpxdwz87drd01m3lwnv82xb4av6kca1xn4w2gmkm";
+    sha256 = "0p03ngsmyz0r5kbpiaq10ns4fxwkjvvawi8k6pfall46b93wizsq";
   };
 
-  sourceRoot = "Box2D-${version}/Box2D";
+  sourceRoot = "box2d-${version}/Box2D";
 
   nativeBuildInputs = [ cmake unzip pkg-config ];
   buildInputs = [ libGLU libGL freeglut libX11 xorgproto libXi ];