diff --git a/codex-rs/core/BUILD.bazel b/codex-rs/core/BUILD.bazel
index cfa077ff1..dbca9ab63 100644
--- a/codex-rs/core/BUILD.bazel
+++ b/codex-rs/core/BUILD.bazel
@@ -46,7 +46,7 @@ codex_rust_crate(
         "//:AGENTS.md",
     ],
     test_shard_counts = {
-        "core-all-test": 8,
+        "core-all-test": 16,
         "core-unit-tests": 8,
     },
     test_tags = ["no-sandbox"],