diff --git a/WORKSPACE b/WORKSPACE
index d6b7625..974a9f8 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -14,10 +14,10 @@ mypy_integration_deps("//:current_mypy_version.txt")
 
 http_archive(
     name = "buildifier_prebuilt",
-    sha256 = "c0c8a5e6caf9a99b037e77ed7a5f17615d50881d0d93de3e85c014705f7914fd",
-    strip_prefix = "buildifier-prebuilt-0.4.1",
+    sha256 = "8ada9d88e51ebf5a1fdff37d75ed41d51f5e677cdbeafb0a22dda54747d6e07e",
+    strip_prefix = "buildifier-prebuilt-6.4.0",
     urls = [
-        "http://github.com/keith/buildifier-prebuilt/archive/0.4.1.tar.gz",
+        "http://github.com/keith/buildifier-prebuilt/archive/6.4.0.tar.gz",
     ],
 )
 
diff --git a/mypy.bzl b/mypy.bzl
index 5517e99..2e90644 100644
--- a/mypy.bzl
+++ b/mypy.bzl
@@ -1,7 +1,7 @@
 "Public API"
 
-load("@bazel_skylib//lib:shell.bzl", "shell")
 load("@bazel_skylib//lib:sets.bzl", "sets")
+load("@bazel_skylib//lib:shell.bzl", "shell")
 load("//:rules.bzl", "MyPyStubsInfo")
 
 MyPyAspectInfo = provider(
@@ -26,7 +26,7 @@ DEFAULT_ATTRS = {
     "_mypy_cli": attr.label(
         default = Label("//mypy"),
         executable = True,
-        cfg = "host",
+        cfg = "exec",
     ),
     "_mypy_config": attr.label(
         default = Label("//:mypy_config"),
diff --git a/test/shell/test_mypy.sh b/test/shell/test_mypy.sh
index 745c24a..d058106 100644
--- a/test/shell/test_mypy.sh
+++ b/test/shell/test_mypy.sh
@@ -42,6 +42,10 @@ test_ok_for_package_roots_regression() {
   action_should_succeed build --aspects //:mypy.bzl%mypy_aspect --output_groups=mypy //test/foo:foo
 }
 
+test_ok_buildifier() {
+  action_should_succeed run //tools/buildifier:buildifier.check
+}
+
 test_fails_on_broken_mypy_typings() {
   action_should_fail build --aspects //:mypy.bzl%mypy_aspect --output_groups=mypy //test:broken_mypy_typings
 }
@@ -70,6 +74,7 @@ main() {
   $runner test_ok_on_valid_imported_mypy_test
   $runner test_ok_on_valid_mypy_test
   $runner test_ok_on_empty_py_library
+  $runner test_ok_buildifier
 
   $runner test_fails_on_broken_imported_mypy_typings
   $runner test_fails_on_broken_imported_mypy_test