diff --git a/src/main/kotlin/org/springframework/data/repository/CrudRepositoryExtensions.kt b/src/main/kotlin/org/springframework/data/repository/CrudRepositoryExtensions.kt
index f70e28a5c..1de6ee321 100644
--- a/src/main/kotlin/org/springframework/data/repository/CrudRepositoryExtensions.kt
+++ b/src/main/kotlin/org/springframework/data/repository/CrudRepositoryExtensions.kt
@@ -23,4 +23,4 @@ package org.springframework.data.repository
  * @author Sebastien Deleuze
  * @since 2.1.4
  */
-fun <T, ID> CrudRepository<T, ID>.findByIdOrNull(id: ID): T? = findById(id).orElse(null)
+fun <T, ID> CrudRepository<T, ID>.findByIdOrNull(id: ID): T? = findById(id!!).orElse(null)
diff --git a/src/test/kotlin/org/springframework/data/mapping/model/KotlinClassGeneratingEntityInstantiatorUnitTests.kt b/src/test/kotlin/org/springframework/data/mapping/model/KotlinClassGeneratingEntityInstantiatorUnitTests.kt
index e6bd7559c..69afcf656 100644
--- a/src/test/kotlin/org/springframework/data/mapping/model/KotlinClassGeneratingEntityInstantiatorUnitTests.kt
+++ b/src/test/kotlin/org/springframework/data/mapping/model/KotlinClassGeneratingEntityInstantiatorUnitTests.kt
@@ -46,7 +46,7 @@ class KotlinClassGeneratingEntityInstantiatorUnitTests {
 
 		every { provider.getParameterValue<String>(any()) }.returnsMany("Walter", "White")
 		every { entity.instanceCreatorMetadata } returns constructor
-		every { entity.type } returns constructor.constructor.declaringClass
+		every { entity.type } returns constructor!!.constructor.declaringClass
 		every { entity.typeInformation } returns mockk()
 
 		val instance: Contact =
@@ -74,7 +74,7 @@ class KotlinClassGeneratingEntityInstantiatorUnitTests {
 		)
 
 		every { entity.instanceCreatorMetadata } returns constructor
-		every { entity.type } returns constructor.constructor.declaringClass
+		every { entity.type } returns constructor!!.constructor.declaringClass
 		every { entity.typeInformation } returns mockk()
 
 		val instance: ContactWithDefaulting = KotlinClassGeneratingEntityInstantiator().createInstance(entity, provider)
@@ -98,7 +98,7 @@ class KotlinClassGeneratingEntityInstantiatorUnitTests {
 
 		every { provider.getParameterValue<Boolean>(any()) } returns null
 		every { entity.instanceCreatorMetadata } returns constructor
-		every { entity.type } returns constructor.constructor.declaringClass
+		every { entity.type } returns constructor!!.constructor.declaringClass
 		every { entity.typeInformation } returns mockk()
 
 		assertThatThrownBy {
@@ -108,7 +108,8 @@ class KotlinClassGeneratingEntityInstantiatorUnitTests {
 			)
 		} //
 			.isInstanceOf(MappingInstantiationException::class.java) //
-			.hasMessageContaining("fun <init>(kotlin.Boolean)") //
+			.hasMessageContaining("init") //
+			.hasMessageContaining("kotlin.Boolean") //
 			.hasCauseInstanceOf(IllegalArgumentException::class.java)
 	}
 
@@ -131,7 +132,7 @@ class KotlinClassGeneratingEntityInstantiatorUnitTests {
 		every { provider.getParameterValue<Char>(any()) } returns null
 		every { provider.getParameterValue<Boolean>(any()) } returns null
 		every { entity.instanceCreatorMetadata } returns constructor
-		every { entity.type } returns constructor.constructor.declaringClass
+		every { entity.type } returns constructor!!.constructor.declaringClass
 		every { entity.typeInformation } returns mockk()
 
 		val instance: WithPrimitiveDefaulting = KotlinClassGeneratingEntityInstantiator().createInstance(entity, provider)
@@ -157,7 +158,7 @@ class KotlinClassGeneratingEntityInstantiatorUnitTests {
 
 		every { provider.getParameterValue<String>(any()) } returns "Walter"
 		every { entity.instanceCreatorMetadata } returns constructor
-		every { entity.type } returns constructor.constructor.declaringClass
+		every { entity.type } returns constructor!!.constructor.declaringClass
 		every { entity.typeInformation } returns mockk()
 
 		val instance: CustomUser =
diff --git a/src/test/kotlin/org/springframework/data/mapping/model/PreferredConstructorDiscovererUnitTests.kt b/src/test/kotlin/org/springframework/data/mapping/model/PreferredConstructorDiscovererUnitTests.kt
index 9121bbf73..75281bcc5 100644
--- a/src/test/kotlin/org/springframework/data/mapping/model/PreferredConstructorDiscovererUnitTests.kt
+++ b/src/test/kotlin/org/springframework/data/mapping/model/PreferredConstructorDiscovererUnitTests.kt
@@ -32,7 +32,7 @@ class PreferredConstructorDiscovererUnitTests {
 
 		val constructor = PreferredConstructorDiscoverer.discover<Simple, SamplePersistentProperty>(Simple::class.java)
 
-		assertThat(constructor.parameters.size).isEqualTo(1)
+		assertThat(constructor!!.parameters.size).isEqualTo(1)
 	}
 
 	@Test // DATACMNS-1126
@@ -40,7 +40,7 @@ class PreferredConstructorDiscovererUnitTests {
 
 		val constructor = PreferredConstructorDiscoverer.discover<TwoConstructors, SamplePersistentProperty>(TwoConstructors::class.java)
 
-		assertThat(constructor.parameters.size).isEqualTo(1)
+		assertThat(constructor!!.parameters.size).isEqualTo(1)
 	}
 
 	@Test // DATACMNS-1170
@@ -48,7 +48,7 @@ class PreferredConstructorDiscovererUnitTests {
 
 		val constructor = PreferredConstructorDiscoverer.discover<TwoConstructorsWithoutDefault, SamplePersistentProperty>(TwoConstructorsWithoutDefault::class.java)
 
-		assertThat(constructor.parameters).isEmpty()
+		assertThat(constructor!!.parameters).isEmpty()
 	}
 
 	@Test // DATACMNS-1126
@@ -56,7 +56,7 @@ class PreferredConstructorDiscovererUnitTests {
 
 		val constructor = PreferredConstructorDiscoverer.discover<AnnotatedConstructors, SamplePersistentProperty>(AnnotatedConstructors::class.java)
 
-		assertThat(constructor.parameters.size).isEqualTo(2)
+		assertThat(constructor!!.parameters.size).isEqualTo(2)
 	}
 
 	@Test // DATACMNS-1126
@@ -64,7 +64,7 @@ class PreferredConstructorDiscovererUnitTests {
 
 		val constructor = PreferredConstructorDiscoverer.discover<DefaultConstructor, SamplePersistentProperty>(DefaultConstructor::class.java)
 
-		assertThat(constructor.parameters.size).isEqualTo(1)
+		assertThat(constructor!!.parameters.size).isEqualTo(1)
 	}
 
 	@Test // DATACMNS-1126
@@ -72,7 +72,7 @@ class PreferredConstructorDiscovererUnitTests {
 
 		val constructor = PreferredConstructorDiscoverer.discover<TwoDefaultConstructorsAnnotated, SamplePersistentProperty>(TwoDefaultConstructorsAnnotated::class.java)
 
-		assertThat(constructor.parameters.size).isEqualTo(3)
+		assertThat(constructor!!.parameters.size).isEqualTo(3)
 	}
 
 	@Test // DATACMNS-1171
diff --git a/src/test/kotlin/org/springframework/data/repository/query/ParameterUnitTests.kt b/src/test/kotlin/org/springframework/data/repository/query/ParameterUnitTests.kt
index 993628d1c..63ebfecba 100644
--- a/src/test/kotlin/org/springframework/data/repository/query/ParameterUnitTests.kt
+++ b/src/test/kotlin/org/springframework/data/repository/query/ParameterUnitTests.kt
@@ -31,7 +31,8 @@ class ParameterUnitTests {
 	@Test // DATACMNS-1508
 	fun `should consider Continuation a special parameter`() {
 
-		val methodParameter = MethodParameter(MyCoroutineRepository::hello.javaMethod, 0)
+		val methodParameter =
+			MethodParameter(MyCoroutineRepository::hello.javaMethod!!, 0)
 		methodParameter.initParameterNameDiscovery(DefaultParameterNameDiscoverer())
 		val parameter = Parameter(methodParameter)