diff --git a/codex-rs/exec/BUILD.bazel b/codex-rs/exec/BUILD.bazel
index 371520dcd9..6aec3e0b77 100644
--- a/codex-rs/exec/BUILD.bazel
+++ b/codex-rs/exec/BUILD.bazel
@@ -3,5 +3,8 @@ load("//:defs.bzl", "codex_rust_crate")
 codex_rust_crate(
     name = "exec",
     crate_name = "codex_exec",
+    test_shard_counts = {
+        "exec-all-test": 8,
+    },
     test_tags = ["no-sandbox"],
 )
diff --git a/codex-rs/shell-command/BUILD.bazel b/codex-rs/shell-command/BUILD.bazel
index 41f2f53f38..6207da9cb1 100644
--- a/codex-rs/shell-command/BUILD.bazel
+++ b/codex-rs/shell-command/BUILD.bazel
@@ -4,4 +4,7 @@ codex_rust_crate(
     name = "shell-command",
     crate_name = "codex_shell_command",
     compile_data = ["src/command_safety/powershell_parser.ps1"],
+    test_shard_counts = {
+        "shell-command-unit-tests": 8,
+    },
 )
diff --git a/codex-rs/state/BUILD.bazel b/codex-rs/state/BUILD.bazel
index e10ac17c90..25d962e80d 100644
--- a/codex-rs/state/BUILD.bazel
+++ b/codex-rs/state/BUILD.bazel
@@ -4,4 +4,7 @@ codex_rust_crate(
     name = "state",
     crate_name = "codex_state",
     compile_data = glob(["logs_migrations/**", "migrations/**"]),
+    test_shard_counts = {
+        "state-unit-tests": 4,
+    },
 )