diff --git a/_itest/builder-itest/src/main/kotlin/MyCustomAnnotationSpec.kt b/_itest/builder-itest/src/main/kotlin/MyCustomAnnotationSpec.kt
index 6bc1138..016a654 100644
--- a/_itest/builder-itest/src/main/kotlin/MyCustomAnnotationSpec.kt
+++ b/_itest/builder-itest/src/main/kotlin/MyCustomAnnotationSpec.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.itest
 
@@ -9,6 +8,7 @@ import io.toolisticon.kotlin.generation.KotlinCodeGeneration.buildFile
 import io.toolisticon.kotlin.generation.itest.KotlinCodeGenerationITestConfig.ROOT_PACKAGE
 
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 object MyCustomAnnotationSpec {
   val name = ClassName(ROOT_PACKAGE, "MyCustomAnnotation")
 
diff --git a/_itest/builder-itest/src/test/kotlin/HelloWorldExampleITest.kt b/_itest/builder-itest/src/test/kotlin/HelloWorldExampleITest.kt
index 17abacf..9f7511c 100644
--- a/_itest/builder-itest/src/test/kotlin/HelloWorldExampleITest.kt
+++ b/_itest/builder-itest/src/test/kotlin/HelloWorldExampleITest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class, ExperimentalCompilerApi::class)
 
 package io.toolisticon.kotlin.generation.itest
 
@@ -14,6 +13,7 @@ import org.assertj.core.api.Assertions.assertThat
 import org.jetbrains.kotlin.compiler.plugin.ExperimentalCompilerApi
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class, ExperimentalCompilerApi::class)
 internal class HelloWorldExampleITest {
 
   @Test
diff --git a/_itest/builder-itest/src/test/kotlin/KotlinFileSpecITest.kt b/_itest/builder-itest/src/test/kotlin/KotlinFileSpecITest.kt
index 6348c15..c6cea9b 100644
--- a/_itest/builder-itest/src/test/kotlin/KotlinFileSpecITest.kt
+++ b/_itest/builder-itest/src/test/kotlin/KotlinFileSpecITest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class, ExperimentalCompilerApi::class)
 package io.toolisticon.kotlin.generation.itest
 
 import com.squareup.kotlinpoet.ClassName
@@ -8,6 +7,7 @@ import io.toolisticon.kotlin.generation.builder.KotlinFileSpecBuilder
 import org.jetbrains.kotlin.compiler.plugin.ExperimentalCompilerApi
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class, ExperimentalCompilerApi::class)
 internal class KotlinFileSpecITest {
 
   @Target(AnnotationTarget.FILE)
diff --git a/_itest/builder-itest/src/test/kotlin/MyCustomAnnotationSpecITest.kt b/_itest/builder-itest/src/test/kotlin/MyCustomAnnotationSpecITest.kt
index 8da29c9..2364625 100644
--- a/_itest/builder-itest/src/test/kotlin/MyCustomAnnotationSpecITest.kt
+++ b/_itest/builder-itest/src/test/kotlin/MyCustomAnnotationSpecITest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class, ExperimentalCompilerApi::class)
 
 package io.toolisticon.kotlin.generation.itest
 
@@ -17,6 +16,7 @@ import org.junit.jupiter.api.Test
 import kotlin.reflect.KClass
 import io.toolisticon.kotlin.generation.test.KotlinCodeGenerationTest.assertThat as assertThatCompilation
 
+@OptIn(ExperimentalKotlinPoetApi::class, ExperimentalCompilerApi::class)
 internal class MyCustomAnnotationSpecITest {
 
   @Test
diff --git a/_itest/spi-itest/src/test/kotlin/SpiITest.kt b/_itest/spi-itest/src/test/kotlin/SpiITest.kt
index 9ff6868..c371675 100644
--- a/_itest/spi-itest/src/test/kotlin/SpiITest.kt
+++ b/_itest/spi-itest/src/test/kotlin/SpiITest.kt
@@ -1,5 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class, ExperimentalCompilerApi::class)
-
 package io.toolisticon.kotlin.generation.itest.spi
 
 import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
@@ -15,6 +13,7 @@ import org.assertj.core.api.Assertions.assertThatThrownBy
 import org.jetbrains.kotlin.compiler.plugin.ExperimentalCompilerApi
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class, ExperimentalCompilerApi::class)
 internal class SpiITest {
 
   @Test
diff --git a/kotlin-code-generation-test/src/main/kotlin/KotlinCodeGenerationTest.kt b/kotlin-code-generation-test/src/main/kotlin/KotlinCodeGenerationTest.kt
index 2417b79..63f4c60 100644
--- a/kotlin-code-generation-test/src/main/kotlin/KotlinCodeGenerationTest.kt
+++ b/kotlin-code-generation-test/src/main/kotlin/KotlinCodeGenerationTest.kt
@@ -1,5 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
-
 package io.toolisticon.kotlin.generation.test
 
 import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
@@ -34,6 +32,7 @@ import java.io.ByteArrayOutputStream
  *  ```
  */
 @ExperimentalCompilerApi
+@ExperimentalKotlinPoetApi
 object KotlinCodeGenerationTest {
 
   fun assertThat(actual: KotlinCompilationResult): KotlinCompilationAssert = KotlinCompilationAssert(actual)
diff --git a/kotlin-code-generation/src/test/kotlin/KotlinCodeGenerationTest.kt b/kotlin-code-generation/src/test/kotlin/KotlinCodeGenerationTest.kt
index 0708f3f..1f3f2ae 100644
--- a/kotlin-code-generation/src/test/kotlin/KotlinCodeGenerationTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/KotlinCodeGenerationTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation
 
@@ -18,6 +17,7 @@ import org.assertj.core.api.Assertions.assertThatThrownBy
 import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KotlinCodeGenerationTest {
 
   @Nested
diff --git a/kotlin-code-generation/src/test/kotlin/TestFixtures.kt b/kotlin-code-generation/src/test/kotlin/TestFixtures.kt
index 3a3358a..e78c2b4 100644
--- a/kotlin-code-generation/src/test/kotlin/TestFixtures.kt
+++ b/kotlin-code-generation/src/test/kotlin/TestFixtures.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation
 
@@ -21,6 +20,7 @@ import java.time.Instant
 import java.util.*
 import kotlin.reflect.KClass
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 object TestFixtures {
 
   // a fixed instant to be used in test with
diff --git a/kotlin-code-generation/src/test/kotlin/_test/MutableSpiRegistry.kt b/kotlin-code-generation/src/test/kotlin/_test/MutableSpiRegistry.kt
index d9ff9ca..8b6a79e 100644
--- a/kotlin-code-generation/src/test/kotlin/_test/MutableSpiRegistry.kt
+++ b/kotlin-code-generation/src/test/kotlin/_test/MutableSpiRegistry.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation._test
 
@@ -10,6 +9,7 @@ import io.toolisticon.kotlin.generation.spi.processor.KotlinCodeGenerationProces
 import io.toolisticon.kotlin.generation.spi.strategy.KotlinCodeGenerationStrategyList
 import kotlin.reflect.KClass
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 class MutableSpiRegistry(
   val strategyList: MutableList<UnboundKotlinCodeGenerationStrategy> = mutableListOf(),
   val processorList: MutableList<UnboundKotlinCodeGenerationProcessor> = mutableListOf(),
diff --git a/kotlin-code-generation/src/test/kotlin/_test/TestContext.kt b/kotlin-code-generation/src/test/kotlin/_test/TestContext.kt
index 39c76e3..4011999 100644
--- a/kotlin-code-generation/src/test/kotlin/_test/TestContext.kt
+++ b/kotlin-code-generation/src/test/kotlin/_test/TestContext.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation._test
 
@@ -6,6 +5,7 @@ import com.squareup.kotlinpoet.ClassName
 import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
 import io.toolisticon.kotlin.generation.spi.KotlinCodeGenerationContext
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 class TestContext(
   val rootClassName: ClassName,
   override val registry: MutableSpiRegistry
diff --git a/kotlin-code-generation/src/test/kotlin/_test/TestDeclarationFileStrategy.kt b/kotlin-code-generation/src/test/kotlin/_test/TestDeclarationFileStrategy.kt
index afd8147..69499f3 100644
--- a/kotlin-code-generation/src/test/kotlin/_test/TestDeclarationFileStrategy.kt
+++ b/kotlin-code-generation/src/test/kotlin/_test/TestDeclarationFileStrategy.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation._test
 
@@ -8,6 +7,7 @@ import io.toolisticon.kotlin.generation.KotlinCodeGeneration.buildFile
 import io.toolisticon.kotlin.generation.spec.KotlinFileSpec
 import io.toolisticon.kotlin.generation.spi.strategy.KotlinFileSpecStrategy
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 class TestDeclarationFileStrategy : KotlinFileSpecStrategy<TestContext, TestDeclaration>(
   contextType = TestContext::class, TestDeclaration::class
 ) {
diff --git a/kotlin-code-generation/src/test/kotlin/poet/KDocTest.kt b/kotlin-code-generation/src/test/kotlin/poet/KDocTest.kt
index 0ef7657..229a6e7 100644
--- a/kotlin-code-generation/src/test/kotlin/poet/KDocTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/poet/KDocTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.poet
 
@@ -7,6 +6,7 @@ import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KDocTest {
 
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/poet/TypeSpecBuilderTest.kt b/kotlin-code-generation/src/test/kotlin/poet/TypeSpecBuilderTest.kt
index 4641670..07d7e7c 100644
--- a/kotlin-code-generation/src/test/kotlin/poet/TypeSpecBuilderTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/poet/TypeSpecBuilderTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.poet
 
@@ -10,6 +9,7 @@ import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class TypeSpecBuilderTest {
 
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinAnnotationClassTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinAnnotationClassTest.kt
index c3f8896..f003408 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinAnnotationClassTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinAnnotationClassTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -8,6 +7,7 @@ import io.toolisticon.kotlin.generation.KotlinCodeGeneration.buildAnnotationClas
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KotlinAnnotationClassTest {
 
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinAnnotationTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinAnnotationTest.kt
index 7c8b882..954585f 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinAnnotationTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinAnnotationTest.kt
@@ -1,5 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
-
 package io.toolisticon.kotlin.generation.spec
 
 import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
@@ -11,6 +9,7 @@ import org.junit.jupiter.api.Test
 import kotlin.reflect.KClass
 
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KotlinAnnotationTest {
 
   annotation class Foo(
@@ -29,13 +28,13 @@ internal class KotlinAnnotationTest {
     assertThat(annotation.code).isEqualTo("""@io.toolisticon.kotlin.generation.TestFixtures.MyAnnotation(name = "foo", type = kotlin.String::class)""");
   }
 
-
   @Test
-  fun `create Foo annotation`() {
+  fun `create Foo annotation - multiline`() {
     val spec = KotlinAnnotationSpecBuilder.builder(Foo::class)
       .addMember("bar = %S", "hello world")
       .addStringMember("x", "foo")
       .addKClassMember("type", Long::class)
+      .multiLine()
       .build()
 
     assertThat(spec.code).isEqualTo("""@io.toolisticon.kotlin.generation.spec.KotlinAnnotationTest.Foo(bar = "hello world", x = "foo", type = kotlin.Long::class)""")
@@ -52,6 +51,28 @@ internal class KotlinAnnotationTest {
     )
   }
 
+  @Test
+  fun `create Foo annotation - singleline`() {
+    val spec = KotlinAnnotationSpecBuilder.builder(Foo::class)
+      .addMember("bar = %S", "hello world")
+      .addStringMember("x", "foo")
+      .addKClassMember("type", Long::class)
+      .build()
+
+    assertThat(spec.code).isEqualTo("""@io.toolisticon.kotlin.generation.spec.KotlinAnnotationTest.Foo(bar = "hello world", x = "foo", type = kotlin.Long::class)""")
+    assertThat(spec.members).hasSize(1)
+
+    assertThat(spec).hasToString(
+      "KotlinAnnotationSpec(" +
+        "typeName=io.toolisticon.kotlin.generation.spec.KotlinAnnotationTest.Foo, " +
+        "members=[" +
+        "bar = \"hello world\", " +
+        "x = \"foo\", " +
+        "type = kotlin.Long::class]" +
+        ")"
+    )
+  }
+
   @Test
   fun `use toBuilder to add members`() {
     var spec = KotlinAnnotationSpecBuilder.builder(Foo::class)
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinAnonymousClassTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinAnonymousClassTest.kt
index 046b7a2..ae0649d 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinAnonymousClassTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinAnonymousClassTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -8,6 +7,7 @@ import io.toolisticon.kotlin.generation.KotlinCodeGeneration.buildFun
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KotlinAnonymousClassTest {
   @Test
   fun build() {
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinCompanionObjectTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinCompanionObjectTest.kt
index 89a3b40..cdb5ef1 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinCompanionObjectTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinCompanionObjectTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -10,6 +9,7 @@ import io.toolisticon.kotlin.generation.KotlinCodeGeneration.format.FORMAT_STRIN
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KotlinCompanionObjectTest {
 
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinConstructorPropertyTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinConstructorPropertyTest.kt
index f0a1441..f86f111 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinConstructorPropertyTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinConstructorPropertyTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -8,6 +7,7 @@ import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.Assumptions.assumeTrue
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 @Deprecated("not implemented yet")
 internal class KotlinConstructorPropertyTest {
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinDataClassTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinDataClassTest.kt
index e744c4f..8c3d686 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinDataClassTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinDataClassTest.kt
@@ -1,5 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
-
 package io.toolisticon.kotlin.generation.spec
 
 import com.squareup.kotlinpoet.ClassName
@@ -11,6 +9,7 @@ import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KotlinDataClassTest {
 
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinEnumClassTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinEnumClassTest.kt
index de6b36b..556314e 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinEnumClassTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinEnumClassTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -7,6 +6,7 @@ import io.toolisticon.kotlin.generation.TestFixtures.notDeprecated
 import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 @Deprecated("not implemented yet")
 internal class KotlinEnumClassTest {
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinFileTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinFileTest.kt
index 63dc18f..1a50c31 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinFileTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinFileTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -7,6 +6,7 @@ import io.toolisticon.kotlin.generation.TestFixtures.notDeprecated
 import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 @Deprecated("not implemented yet")
 internal class KotlinFileTest {
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinFunTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinFunTest.kt
index 7b90a3c..d0d8db6 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinFunTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinFunTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -7,6 +6,7 @@ import io.toolisticon.kotlin.generation.TestFixtures.notDeprecated
 import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 @Deprecated("not implemented yet")
 internal class KotlinFunTest {
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinInterfaceTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinInterfaceTest.kt
index 546c57c..3f474ed 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinInterfaceTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinInterfaceTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -7,6 +6,7 @@ import io.toolisticon.kotlin.generation.TestFixtures.notDeprecated
 import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 @Deprecated("not implemented yet")
 internal class KotlinInterfaceTest {
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinObjectTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinObjectTest.kt
index 0487b81..0862dd8 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinObjectTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinObjectTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -7,6 +6,7 @@ import io.toolisticon.kotlin.generation.TestFixtures.notDeprecated
 import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 @Deprecated("not implemented yet")
 internal class KotlinObjectTest {
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinParameterTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinParameterTest.kt
index f694b45..672bfa5 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinParameterTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinParameterTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -7,6 +6,7 @@ import io.toolisticon.kotlin.generation.TestFixtures.notDeprecated
 import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 @Deprecated("not implemented yet")
 internal class KotlinParameterTest {
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinPropertyTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinPropertyTest.kt
index 9ca283b..f93c58f 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinPropertyTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinPropertyTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -7,6 +6,7 @@ import io.toolisticon.kotlin.generation.TestFixtures.notDeprecated
 import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 @Deprecated("not implemented yet")
 internal class KotlinPropertyTest {
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinTypeAliasTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinTypeAliasTest.kt
index c23b0f2..b428222 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinTypeAliasTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinTypeAliasTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spec
 
@@ -7,6 +6,7 @@ import io.toolisticon.kotlin.generation.TestFixtures.notDeprecated
 import org.junit.jupiter.api.Assumptions.assumeFalse
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 @Deprecated("not implemented yet")
 internal class KotlinTypeAliasTest {
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spec/KotlinValueClassTest.kt b/kotlin-code-generation/src/test/kotlin/spec/KotlinValueClassTest.kt
index e77ff0a..65e1f9a 100644
--- a/kotlin-code-generation/src/test/kotlin/spec/KotlinValueClassTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spec/KotlinValueClassTest.kt
@@ -1,5 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
-
 package io.toolisticon.kotlin.generation.spec
 
 import com.squareup.kotlinpoet.ClassName
@@ -9,6 +7,7 @@ import io.toolisticon.kotlin.generation.TestFixtures
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KotlinValueClassTest {
 
   @Test
diff --git a/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationServiceRepositoryTest.kt b/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationServiceRepositoryTest.kt
index 56fc63b..c72b324 100644
--- a/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationServiceRepositoryTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationServiceRepositoryTest.kt
@@ -1,5 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
-
 package io.toolisticon.kotlin.generation.spi
 
 import com.squareup.kotlinpoet.ExperimentalKotlinPoetApi
@@ -7,12 +5,13 @@ import io.toolisticon.kotlin.generation.KotlinCodeGeneration
 import io.toolisticon.kotlin.generation.spec.KotlinDataClassSpec
 import io.toolisticon.kotlin.generation.spi.context.KotlinCodeGenerationContextBase
 import io.toolisticon.kotlin.generation.spi.registry.KotlinCodeGenerationServiceRepository
-import io.toolisticon.kotlin.generation.spi.strategy.KotlinDataClassSpecStrategy
 import io.toolisticon.kotlin.generation.spi.strategy.KotlinCodeGenerationStrategyList
+import io.toolisticon.kotlin.generation.spi.strategy.KotlinDataClassSpecStrategy
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 import kotlin.reflect.KClass
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KotlinCodeGenerationServiceRepositoryTest {
 
   class TestContext(registry: KotlinCodeGenerationSpiRegistry) : KotlinCodeGenerationContextBase<TestContext>(registry) {
diff --git a/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationStrategyListTest.kt b/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationStrategyListTest.kt
index 28f6ae4..58bcdde 100644
--- a/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationStrategyListTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spi/KotlinCodeGenerationStrategyListTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spi
 
@@ -18,6 +17,7 @@ import io.toolisticon.kotlin.generation.spi.strategy.executeSingle
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 class KotlinCodeGenerationStrategyListTest {
 
   class AStrategy : DataClassAStrategy() {
diff --git a/kotlin-code-generation/src/test/kotlin/spi/ServiceLoaderTestClassLoaderTest.kt b/kotlin-code-generation/src/test/kotlin/spi/ServiceLoaderTestClassLoaderTest.kt
index f5d5e65..64d3e82 100644
--- a/kotlin-code-generation/src/test/kotlin/spi/ServiceLoaderTestClassLoaderTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spi/ServiceLoaderTestClassLoaderTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spi
 
@@ -8,6 +7,7 @@ import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 import java.util.ServiceLoader
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 class ServiceLoaderTestClassLoaderTest {
 
   interface MyInterface {
diff --git a/kotlin-code-generation/src/test/kotlin/spi/processor/KotlinAnnotationClassSpecProcessorTest.kt b/kotlin-code-generation/src/test/kotlin/spi/processor/KotlinAnnotationClassSpecProcessorTest.kt
index 6b9081b..61e1f75 100644
--- a/kotlin-code-generation/src/test/kotlin/spi/processor/KotlinAnnotationClassSpecProcessorTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/spi/processor/KotlinAnnotationClassSpecProcessorTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.spi.processor
 
@@ -12,6 +11,7 @@ import io.toolisticon.kotlin.generation.spec.toFileSpec
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class KotlinAnnotationClassSpecProcessorTest {
 
   class AddRetentionProcessor : KotlinAnnotationClassSpecProcessor<TestContext, TestInput>(
diff --git a/kotlin-code-generation/src/test/kotlin/support/SuppressAnnotationTest.kt b/kotlin-code-generation/src/test/kotlin/support/SuppressAnnotationTest.kt
index 867f182..d53fc54 100644
--- a/kotlin-code-generation/src/test/kotlin/support/SuppressAnnotationTest.kt
+++ b/kotlin-code-generation/src/test/kotlin/support/SuppressAnnotationTest.kt
@@ -1,4 +1,3 @@
-@file:OptIn(ExperimentalKotlinPoetApi::class)
 
 package io.toolisticon.kotlin.generation.support
 
@@ -9,6 +8,7 @@ import io.toolisticon.kotlin.generation.KotlinCodeGeneration.builder.fileBuilder
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
+@OptIn(ExperimentalKotlinPoetApi::class)
 internal class SuppressAnnotationTest {
   private val className = ClassName("foo", "Bar")
   private val typeBuilder = classBuilder(className)