diff --git a/src/jvm/main/org/jetbrains/kotlinx/lincheck/Utils.kt b/src/jvm/main/org/jetbrains/kotlinx/lincheck/Utils.kt
index a6aedc54a..f380e2e23 100644
--- a/src/jvm/main/org/jetbrains/kotlinx/lincheck/Utils.kt
+++ b/src/jvm/main/org/jetbrains/kotlinx/lincheck/Utils.kt
@@ -329,3 +329,20 @@ internal inline fun <R> runOutsideIgnoredSection(descriptor: ThreadDescriptor?,
 
 internal const val LINCHECK_PACKAGE_NAME = "org.jetbrains.kotlinx.lincheck."
 internal const val LINCHECK_RUNNER_PACKAGE_NAME = "org.jetbrains.kotlinx.lincheck.runner."
+
+internal fun <T> Class<T>.newDefaultInstance(): T {
+    @Suppress("UNCHECKED_CAST")
+    val constructor = this.declaredConstructors.singleOrNull { it.parameterCount == 0 } as? Constructor<T>
+    if (constructor != null) {
+        return constructor.newInstance()
+    }
+
+    if (this.enclosingClass != null) {
+        val enclosingObject = this.enclosingClass.newDefaultInstance()
+        return this.getDeclaredConstructor(this.enclosingClass)
+            .also { it.isAccessible = true }
+            .newInstance(enclosingObject)
+    }
+
+    throw IllegalStateException("No suitable constructor found for ${this.canonicalName}")
+}
\ No newline at end of file
diff --git a/src/jvm/main/org/jetbrains/kotlinx/lincheck/runner/ParallelThreadsRunner.kt b/src/jvm/main/org/jetbrains/kotlinx/lincheck/runner/ParallelThreadsRunner.kt
index acf05a799..3f49e0269 100644
--- a/src/jvm/main/org/jetbrains/kotlinx/lincheck/runner/ParallelThreadsRunner.kt
+++ b/src/jvm/main/org/jetbrains/kotlinx/lincheck/runner/ParallelThreadsRunner.kt
@@ -180,8 +180,7 @@ internal open class ParallelThreadsRunner(
     private var ensuredTestInstanceIsTransformed = false
 
     private fun createTestInstance() {
-        @Suppress("DEPRECATION")
-        testInstance = testClass.newInstance()
+        testInstance = testClass.newDefaultInstance()
         if (strategy is ModelCheckingStrategy) {
             // In the model checking mode, we need to ensure
             // that all the necessary classes and instrumented
diff --git a/src/jvm/main/org/jetbrains/kotlinx/lincheck/verifier/LTS.kt b/src/jvm/main/org/jetbrains/kotlinx/lincheck/verifier/LTS.kt
index 2f8974513..74189e0e6 100644
--- a/src/jvm/main/org/jetbrains/kotlinx/lincheck/verifier/LTS.kt
+++ b/src/jvm/main/org/jetbrains/kotlinx/lincheck/verifier/LTS.kt
@@ -261,8 +261,7 @@ class LTS(private val sequentialSpecification: Class<*>) {
     }
 
     private fun createInitialStateInstance(): Any {
-        @Suppress("DEPRECATION")
-        return sequentialSpecification.newInstance().also {
+        return sequentialSpecification.newDefaultInstance().also {
             // the sequential version of the data structure used for verification
             // may differ from the original parallel version,
             // in this case we need to ensure that the sequential class is also instrumented
diff --git a/src/jvm/test/org/jetbrains/kotlinx/lincheck_test/runner/InnerClassTest.kt b/src/jvm/test/org/jetbrains/kotlinx/lincheck_test/runner/InnerClassTest.kt
new file mode 100644
index 000000000..2ca17fb73
--- /dev/null
+++ b/src/jvm/test/org/jetbrains/kotlinx/lincheck_test/runner/InnerClassTest.kt
@@ -0,0 +1,46 @@
+/*
+ * Lincheck
+ *
+ * Copyright (C) 2019 - 2025 JetBrains s.r.o.
+ *
+ * This Source Code Form is subject to the terms of the
+ * Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed
+ * with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+package org.jetbrains.kotlinx.lincheck_test.runner
+
+import org.jetbrains.kotlinx.lincheck.annotations.Operation
+import org.jetbrains.kotlinx.lincheck.check
+import org.jetbrains.kotlinx.lincheck.strategy.stress.StressOptions
+import org.junit.Test
+
+class OuterClass {
+    inner class InnerClass {
+        @Operation
+        fun zero() = 0
+    }
+
+    class NestedClass {
+        @Operation
+        fun zero() = 0
+    }
+}
+
+class InnerClassTest {
+    @Test
+    fun testInnerClass() {
+        StressOptions()
+            .invocationsPerIteration(1)
+            .iterations(1)
+            .check(OuterClass.InnerClass::class)
+    }
+
+    @Test
+    fun testNestedClass() {
+        StressOptions()
+            .invocationsPerIteration(1)
+            .iterations(1)
+            .check(OuterClass.NestedClass::class)
+    }
+}