diff --git a/tests/kernels/test_cache.py b/tests/kernels/test_cache.py
index 3749592a0ec71..1d8d41e013b03 100644
--- a/tests/kernels/test_cache.py
+++ b/tests/kernels/test_cache.py
@@ -49,13 +49,12 @@ def test_copy_blocks(
     src_blocks = random.sample(range(num_blocks), num_mappings)
     remainig_blocks = list(set(range(num_blocks)) - set(src_blocks))
     dst_blocks = random.sample(remainig_blocks, 2 * num_mappings)
-    copy_src = []
-    copy_dst = []
+    block_mapping = {}
     for i in range(num_mappings):
-        copy_src.append(src_blocks[i])
-        copy_dst.append(dst_blocks[2 * i])
-        copy_src.append(src_blocks[i])
-        copy_dst.append(dst_blocks[2 * i + 1])
+        src = src_blocks[i]
+        dst1 = dst_blocks[2 * i]
+        dst2 = dst_blocks[2 * i + 1]
+        block_mapping[src] = [dst1, dst2]
 
     # Create the KV caches.
     key_caches, value_caches = kv_cache_factory(num_blocks, block_size,
@@ -67,14 +66,15 @@ def test_copy_blocks(
     cloned_value_caches = [value_cache.clone() for value_cache in value_caches]
 
     # Call the copy blocks kernel.
-    cache_ops.copy_blocks(key_caches, value_caches, copy_src, copy_dst)
+    cache_ops.copy_blocks(key_caches, value_caches, block_mapping)
 
     # Run the reference implementation.
-    for src, dst in zip(copy_src, copy_dst):
-        for cloned_key_cache in cloned_key_caches:
-            cloned_key_cache[dst].copy_(cloned_key_cache[src])
-        for cloned_value_cache in cloned_value_caches:
-            cloned_value_cache[dst].copy_(cloned_value_cache[src])
+    for src, dsts in block_mapping.items():
+        for dst in dsts:
+            for cloned_key_cache in cloned_key_caches:
+                cloned_key_cache[dst].copy_(cloned_key_cache[src])
+            for cloned_value_cache in cloned_value_caches:
+                cloned_value_cache[dst].copy_(cloned_value_cache[src])
 
     # Compare the results.
     for key_cache, cloned_key_cache in zip(key_caches, cloned_key_caches):