diff --git a/app-proto/inversive-display/src/main.rs b/app-proto/inversive-display/src/main.rs
index 72846fc..5afbb04 100644
--- a/app-proto/inversive-display/src/main.rs
+++ b/app-proto/inversive-display/src/main.rs
@@ -150,6 +150,9 @@ fn main() {
             let vertex_array = ctx.create_vertex_array().unwrap();
             ctx.bind_vertex_array(Some(&vertex_array));
             
+            // enable depth testing
+            ctx.enable(WebGl2RenderingContext::DEPTH_TEST);
+            
             // set the projection map
             let focal_length = 3.0_f32;
             let near_clip = 0.1_f32;
@@ -158,8 +161,8 @@ fn main() {
             let world_to_clip: [f32; 16] = [
                 focal_length, 0.0, 0.0, 0.0,
                 0.0, focal_length, 0.0, 0.0,
-                0.0, 0.0, (near_clip + far_clip) * depth_inv, -1.,
-                0.0, 0.0, 2. * near_clip * far_clip * depth_inv, 0.0
+                0.0, 0.0, -(near_clip + far_clip) * depth_inv, -1.,
+                0.0, 0.0, -2. * near_clip * far_clip * depth_inv, 0.0
             ];
             ctx.uniform_matrix4fv_with_f32_array(world_to_clip_loc.as_ref(), false, &world_to_clip);