open up the test runners main class
diff --git a/kotlin/internal/rules.bzl b/kotlin/internal/rules.bzl
index 93047ab..70ef7c8 100644
--- a/kotlin/internal/rules.bzl
+++ b/kotlin/internal/rules.bzl
@@ -85,7 +85,7 @@
     utils.actions.write_launcher(
         ctx,
         transitive_runtime_jars,
-        main_class = "com.google.testing.junit.runner.BazelTestRunner",
+        main_class = ctx.attr.main_class,
         jvm_flags = launcherJvmFlags + ctx.attr.jvm_flags,
     )
     return compile.make_providers(
diff --git a/kotlin/kotlin.bzl b/kotlin/kotlin.bzl
index 346db07..e1f564a 100644
--- a/kotlin/kotlin.bzl
+++ b/kotlin/kotlin.bzl
@@ -320,7 +320,7 @@
             allow_files = True,
         ),
         "test_class": attr.string(),
-        #      "main_class": attr.string(),
+        "main_class": attr.string(default="com.google.testing.junit.runner.BazelTestRunner"),
     }.items()),
     executable = True,
     outputs = _binary_outputs,