diff --git a/.bazelignore b/.bazelignore
index 2b29f27..23758d5 100644
--- a/.bazelignore
+++ b/.bazelignore
@@ -1 +1 @@
-tests
+tests/bcr
diff --git a/.bcr/presubmit.yml b/.bcr/presubmit.yml
index bc6b157..2261133 100644
--- a/.bcr/presubmit.yml
+++ b/.bcr/presubmit.yml
@@ -1,5 +1,5 @@
 bcr_test_module:
-  module_path: tests
+  module_path: tests/bcr
   matrix:
     platform:
       - debian10
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 60e24eb..17eb3d3 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,6 +8,16 @@ on:
     - cron: '0 0 * * *'
 
 jobs:
+  root_module:
+    name: Root module
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Test
+        run: bazel test //...
+
   test_module:
     name: BCR test module
     runs-on: ${{ matrix.os }}
@@ -22,7 +32,7 @@ jobs:
       - name: Test
         env:
           USE_BAZEL_VERSION: ${{ matrix.bazel }}
-        working-directory: tests
+        working-directory: tests/bcr
         run: |
           bazel run //:run_buildozer
           bazel test //...
diff --git a/.gitignore b/.gitignore
index 239b061..e97e787 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,3 @@
 /bazel-*
-/tests/bazel-*
+/tests/bcr/bazel-*
 MODULE.bazel.lock
diff --git a/BUILD.bazel b/BUILD.bazel
index 3bfa071..0c25f2d 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -7,10 +7,14 @@ sh_binary(
     env = {
         "BUILDOZER_RLOCATIONPATH": "$(rlocationpath @buildozer_binary//:buildozer.exe)",
     },
-    visibility = ["//visibility:public"],
     deps = [
         "@bazel_tools//tools/bash/runfiles",
     ],
 )
 
-exports_files(["buildozer_binary.bzl"])
+exports_files(["buildozer.bzl"])
+
+exports_files(
+    ["MODULE.bazel"],
+    visibility = ["//tests:__subpackages__"],
+)
diff --git a/MODULE.bazel b/MODULE.bazel
index 0a4e272..e62b577 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -15,3 +15,5 @@ buildozer_binary.buildozer(
     },
 )
 use_repo(buildozer_binary, "buildozer_binary")
+
+bazel_dep(name = "platforms", version = "0.0.7", dev_dependency = True)
diff --git a/tests/BUILD.bazel b/tests/BUILD.bazel
index cd46c4f..be7f994 100644
--- a/tests/BUILD.bazel
+++ b/tests/BUILD.bazel
@@ -1,7 +1,16 @@
-sh_binary(
-    name = "run_buildozer",
+sh_test(
+    name = "no_deps_test",
+    srcs = ["no_deps_test.sh"],
+    data = [
+        "//:MODULE.bazel",
+        "@buildozer_binary//:buildozer.exe",
+    ],
     env = {
-        "MSYS2_ARG_CONV_EXCL": "*",
+        "BUILDOZER": "$(rootpath @buildozer_binary//:buildozer.exe)",
     },
-    srcs = ["run_buildozer.sh"],
+    target_compatible_with = select({
+        "@platforms//os:linux": [],
+        "@platforms//os:macos": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
diff --git a/tests/.bazelrc b/tests/bcr/.bazelrc
similarity index 100%
rename from tests/.bazelrc
rename to tests/bcr/.bazelrc
diff --git a/tests/bcr/BUILD.bazel b/tests/bcr/BUILD.bazel
new file mode 100644
index 0000000..cd46c4f
--- /dev/null
+++ b/tests/bcr/BUILD.bazel
@@ -0,0 +1,7 @@
+sh_binary(
+    name = "run_buildozer",
+    env = {
+        "MSYS2_ARG_CONV_EXCL": "*",
+    },
+    srcs = ["run_buildozer.sh"],
+)
diff --git a/tests/MODULE.bazel b/tests/bcr/MODULE.bazel
similarity index 94%
rename from tests/MODULE.bazel
rename to tests/bcr/MODULE.bazel
index 0ab8b33..302df8b 100644
--- a/tests/MODULE.bazel
+++ b/tests/bcr/MODULE.bazel
@@ -1,7 +1,7 @@
 bazel_dep(name = "buildozer", version = "")
 local_path_override(
     module_name = "buildozer",
-    path = "..",
+    path = "../..",
 )
 
 repo_ext = use_extension("//:deps.bzl", "repo_ext")
diff --git a/tests/WORKSPACE b/tests/bcr/WORKSPACE
similarity index 100%
rename from tests/WORKSPACE
rename to tests/bcr/WORKSPACE
diff --git a/tests/WORKSPACE.bzlmod b/tests/bcr/WORKSPACE.bzlmod
similarity index 100%
rename from tests/WORKSPACE.bzlmod
rename to tests/bcr/WORKSPACE.bzlmod
diff --git a/tests/bazel_run_test/BUILD.bazel b/tests/bcr/bazel_run_test/BUILD.bazel
similarity index 100%
rename from tests/bazel_run_test/BUILD.bazel
rename to tests/bcr/bazel_run_test/BUILD.bazel
diff --git a/tests/bazel_run_test/bazel_run_test.sh b/tests/bcr/bazel_run_test/bazel_run_test.sh
similarity index 100%
rename from tests/bazel_run_test/bazel_run_test.sh
rename to tests/bcr/bazel_run_test/bazel_run_test.sh
diff --git a/tests/deps.bzl b/tests/bcr/deps.bzl
similarity index 100%
rename from tests/deps.bzl
rename to tests/bcr/deps.bzl
diff --git a/tests/repo_rule_test/BUILD.bazel b/tests/bcr/repo_rule_test/BUILD.bazel
similarity index 100%
rename from tests/repo_rule_test/BUILD.bazel
rename to tests/bcr/repo_rule_test/BUILD.bazel
diff --git a/tests/run_buildozer.sh b/tests/bcr/run_buildozer.sh
similarity index 100%
rename from tests/run_buildozer.sh
rename to tests/bcr/run_buildozer.sh
diff --git a/tests/no_deps_test.sh b/tests/no_deps_test.sh
new file mode 100755
index 0000000..7e01562
--- /dev/null
+++ b/tests/no_deps_test.sh
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+# Verify that the buildozer module has no non-dev dependencies.
+
+set -euo pipefail
+
+# Fail on lines that don't end with " True".
+! $BUILDOZER 'print name dev_dependency' //MODULE.bazel:%bazel_dep \
+    | grep -v ' True$'