diff --git a/wgpu/tests/vertex_indexes/draw.vert.wgsl b/wgpu/tests/vertex_indexes/draw.vert.wgsl
index 3e0abbbbd2..618c545956 100644
--- a/wgpu/tests/vertex_indexes/draw.vert.wgsl
+++ b/wgpu/tests/vertex_indexes/draw.vert.wgsl
@@ -13,4 +13,6 @@ fn vs_main([[builtin(vertex_index)]] instance: u32, [[builtin(vertex_index)]] in
 }
 
 [[stage(fragment)]]
-fn fs_main() -> [[location(0)]] vec4<f32>
\ No newline at end of file
+fn fs_main() -> [[location(0)]] vec4<f32> {
+    return vec4<f32>(0.0);
+}