diff --git a/robolectric-extension/src/main/kotlin/tech/apter/junit/jupiter/robolectric/internal/JUnit5RobolectricTestRunner.kt b/robolectric-extension/src/main/kotlin/tech/apter/junit/jupiter/robolectric/internal/JUnit5RobolectricTestRunner.kt
index c50dc33..141d2c4 100644
--- a/robolectric-extension/src/main/kotlin/tech/apter/junit/jupiter/robolectric/internal/JUnit5RobolectricTestRunner.kt
+++ b/robolectric-extension/src/main/kotlin/tech/apter/junit/jupiter/robolectric/internal/JUnit5RobolectricTestRunner.kt
@@ -16,9 +16,6 @@ import tech.apter.junit.jupiter.robolectric.internal.extensions.hasTheSameParame
 import tech.apter.junit.jupiter.robolectric.internal.extensions.outerMostDeclaringClass
 import java.lang.reflect.Method
 import java.util.concurrent.ConcurrentHashMap
-import java.util.concurrent.locks.Lock
-import java.util.concurrent.locks.ReentrantReadWriteLock
-import kotlin.concurrent.withLock
 
 internal data class TestClassContainer(val testClass: Class<*>)
 
@@ -74,7 +71,7 @@ internal class JUnit5RobolectricTestRunner(
         frameworkMethod: FrameworkMethod,
         bootstrappedMethod: Method,
     ) {
-        beforeTestLock(testClass.javaClass).withLock {
+        synchronized(beforeTestLock) {
             logger.trace { "runBeforeTest ${bootstrappedMethod.declaringClass.simpleName}::${bootstrappedMethod.name}" }
             super.beforeTest(sdkEnvironment, frameworkMethod, bootstrappedMethod)
         }
@@ -131,7 +128,7 @@ internal class JUnit5RobolectricTestRunner(
     }
 
     private companion object {
-        private val beforeTestLocks = ConcurrentHashMap<String, ReentrantReadWriteLock>()
+        private val beforeTestLock = Any()
         private val sdkSandboxParentClassLoaderCache = ConcurrentHashMap<String, ClassLoader>()
 
         private fun defaultInjectorBuilder() =
@@ -139,11 +136,6 @@ internal class JUnit5RobolectricTestRunner(
                 .bind(MavenDependencyResolver::class.java, JUnit5MavenDependencyResolver::class.java)
                 .bind(SandboxManager::class.java, JUnit5RobolectricSandboxManager::class.java)
 
-        private fun beforeTestLock(testClass: Class<*>): Lock =
-            beforeTestLocks.getOrPut(testClass.outerMostDeclaringClass().name) {
-                ReentrantReadWriteLock()
-            }.writeLock()
-
         private fun createParentClassLoader(testClass: Class<*>) =
             sdkSandboxParentClassLoaderCache.getOrPut(testClass.outerMostDeclaringClass().name) {
                 createLogger().trace {