diff --git a/tests/tests/dispatch_workgroups_indirect.rs b/tests/tests/dispatch_workgroups_indirect.rs
index a59bfdc2689..85503f1ee39 100644
--- a/tests/tests/dispatch_workgroups_indirect.rs
+++ b/tests/tests/dispatch_workgroups_indirect.rs
@@ -63,12 +63,14 @@ async fn run_test(
 ) -> [u32; 3] {
     const SHADER_SRC: &str = "
         @group(0) @binding(0)
-        var<storage, read_write> out: vec3<u32>;
+        var<storage, read_write> out: array<u32, 3>;
 
         @compute @workgroup_size(1)
         fn main(@builtin(num_workgroups) num_workgroups: vec3<u32>, @builtin(workgroup_id) workgroup_id: vec3<u32>) {
             if (all(workgroup_id == vec3<u32>())) {
-                out = num_workgroups;
+                out[0] = num_workgroups.x;
+                out[1] = num_workgroups.y;
+                out[2] = num_workgroups.z;
             }
         }
     ";