diff --git a/src/webgpu/api/validation/encoding/cmds/index_access.spec.ts b/src/webgpu/api/validation/encoding/cmds/index_access.spec.ts
index 6c6ff908e01b..cb1aaecb60b7 100644
--- a/src/webgpu/api/validation/encoding/cmds/index_access.spec.ts
+++ b/src/webgpu/api/validation/encoding/cmds/index_access.spec.ts
@@ -129,17 +129,22 @@ class F extends ValidationTest {
 export const g = makeTestGroup(F);
 
 g.test('out_of_bounds')
-  .params(
-    params()
-      .combine(pbool('indirect')) // indirect drawIndexed
-      .combine([
-        { indexCount: 6, firstIndex: 1 }, // indexCount + firstIndex out of bound
-        { indexCount: 6, firstIndex: 6 }, // only firstIndex out of bound
-        { indexCount: 6, firstIndex: 10000 }, // firstIndex much larger than the bound
-        { indexCount: 7, firstIndex: 0 }, // only indexCount out of bound
-        { indexCount: 10000, firstIndex: 0 }, // indexCount much larger than the bound
-      ] as const)
-      .combine(poptions('instanceCount', [1, 10000])) // normal and large instanceCount
+  .cases(pbool('indirect'))
+  .subcases(
+    () =>
+      params()
+        .combine([
+          { indexCount: 6, firstIndex: 1 }, // indexCount + firstIndex out of bound
+          { indexCount: 0, firstIndex: 6 }, // indexCount is 0 but firstIndex out of bound
+          { indexCount: 6, firstIndex: 6 }, // only firstIndex out of bound
+          { indexCount: 6, firstIndex: 10000 }, // firstIndex much larger than the bound
+          { indexCount: 7, firstIndex: 0 }, // only indexCount out of bound
+          { indexCount: 10000, firstIndex: 0 }, // indexCount much larger than the bound
+          { indexCount: 0xffffffff, firstIndex: 0xffffffff }, // max uint32 value
+          { indexCount: 0xffffffff, firstIndex: 2 }, // max uint32 indexCount and small firstIndex
+          { indexCount: 2, firstIndex: 0xffffffff }, // small indexCount and max uint32 firstIndex
+        ] as const)
+        .combine(poptions('instanceCount', [1, 10000])) // normal and large instanceCount
   )
   .fn(t => {
     const { indirect, indexCount, firstIndex, instanceCount } = t.params;