diff --git a/spring-core/src/main/java/org/springframework/core/MethodParameter.java b/spring-core/src/main/java/org/springframework/core/MethodParameter.java
index ad3b190f629..a44ce5898a7 100644
--- a/spring-core/src/main/java/org/springframework/core/MethodParameter.java
+++ b/spring-core/src/main/java/org/springframework/core/MethodParameter.java
@@ -29,6 +29,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
 import kotlin.reflect.KFunction;
@@ -759,17 +760,21 @@ public class MethodParameter {
 			}
 			else {
 				KFunction<?> function = null;
+				Predicate<KParameter> predicate = null;
 				if (method != null) {
 					function = ReflectJvmMapping.getKotlinFunction(method);
+					predicate = p -> KParameter.Kind.VALUE.equals(p.getKind());
 				}
 				else if (ctor != null) {
 					function = ReflectJvmMapping.getKotlinFunction(ctor);
+					predicate = p -> KParameter.Kind.VALUE.equals(p.getKind()) ||
+							KParameter.Kind.INSTANCE.equals(p.getKind());
 				}
 				if (function != null) {
 					List<KParameter> parameters = function.getParameters();
 					KParameter parameter = parameters
 							.stream()
-							.filter(p -> KParameter.Kind.VALUE.equals(p.getKind()))
+							.filter(predicate)
 							.collect(Collectors.toList())
 							.get(index);
 					return (parameter.getType().isMarkedNullable() || parameter.isOptional());
diff --git a/spring-core/src/test/kotlin/org/springframework/core/KotlinMethodParameterTests.kt b/spring-core/src/test/kotlin/org/springframework/core/KotlinMethodParameterTests.kt
index 2157099a4ce..7580f254136 100644
--- a/spring-core/src/test/kotlin/org/springframework/core/KotlinMethodParameterTests.kt
+++ b/spring-core/src/test/kotlin/org/springframework/core/KotlinMethodParameterTests.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,15 +13,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package org.springframework.core
 
-import java.lang.reflect.Method
-
-import org.junit.Before
 import org.junit.Test
-
 import org.junit.Assert.*
+import java.lang.reflect.Method
 
 /**
  * Tests for Kotlin support in [MethodParameter].
@@ -32,36 +28,58 @@ import org.junit.Assert.*
  */
 class KotlinMethodParameterTests {
 
-	lateinit var nullableMethod: Method
+	private val nullableMethod: Method = javaClass.getMethod("nullable", String::class.java)
 
-	lateinit var nonNullableMethod: Method
+	private val nonNullableMethod = javaClass.getMethod("nonNullable", String::class.java)
 
+	private val innerClassConstructor = InnerClass::class.java.getConstructor(KotlinMethodParameterTests::class.java)
 
-	@Before
-	@Throws(NoSuchMethodException::class)
-	fun setup() {
-		nullableMethod = javaClass.getMethod("nullable", String::class.java)
-		nonNullableMethod = javaClass.getMethod("nonNullable", String::class.java)
-	}
+	private val innerClassWithParametersConstructor = InnerClassWithParameter::class.java
+			.getConstructor(KotlinMethodParameterTests::class.java, String::class.java, String::class.java)
+
+	private val regularClassConstructor = RegularClass::class.java.getConstructor(String::class.java, String::class.java)
 
 
 	@Test
 	fun `Method parameter nullability`() {
-		assertTrue(MethodParameter(nullableMethod, 0).isOptional())
-		assertFalse(MethodParameter(nonNullableMethod, 0).isOptional())
+		assertTrue(MethodParameter(nullableMethod, 0).isOptional)
+		assertFalse(MethodParameter(nonNullableMethod, 0).isOptional)
 	}
 
 	@Test
 	fun `Method return type nullability`() {
-		assertTrue(MethodParameter(nullableMethod, -1).isOptional())
-		assertFalse(MethodParameter(nonNullableMethod, -1).isOptional())
+		assertTrue(MethodParameter(nullableMethod, -1).isOptional)
+		assertFalse(MethodParameter(nonNullableMethod, -1).isOptional)
+	}
+
+	@Test  // SPR-17222
+	fun `Inner class constructor`() {
+		assertFalse(MethodParameter(innerClassConstructor, 0).isOptional)
+
+		assertFalse(MethodParameter(innerClassWithParametersConstructor, 0).isOptional)
+		assertFalse(MethodParameter(innerClassWithParametersConstructor, 1).isOptional)
+		assertTrue(MethodParameter(innerClassWithParametersConstructor, 2).isOptional)
+	}
+
+	@Test
+	fun `Regular class constructor`() {
+		assertFalse(MethodParameter(regularClassConstructor, 0).isOptional)
+		assertTrue(MethodParameter(regularClassConstructor, 1).isOptional)
 	}
 
 
-	@Suppress("unused", "unused_parameter")
-	fun nullable(p1: String?): Int? = 42
+	@Suppress("unused_parameter")
+	fun nullable(nullable: String?): Int? = 42
+
+	@Suppress("unused_parameter")
+	fun nonNullable(nonNullable: String): Int = 42
+
+	inner class InnerClass
+
+	@Suppress("unused_parameter")
+	inner class InnerClassWithParameter(nonNullable: String, nullable: String?)
 
-	@Suppress("unused", "unused_parameter")
-	fun nonNullable(p1: String): Int = 42
+	@Suppress("unused_parameter")
+	class RegularClass(nonNullable: String, nullable: String?)
 
 }
diff --git a/src/docs/asciidoc/languages/kotlin.adoc b/src/docs/asciidoc/languages/kotlin.adoc
index 140742e40c0..f4d9667dc2b 100644
--- a/src/docs/asciidoc/languages/kotlin.adoc
+++ b/src/docs/asciidoc/languages/kotlin.adoc
@@ -143,6 +143,10 @@ for serializing / deserializing JSON data is automatically registered when
 found in the classpath and a warning message will be logged if Jackson and Kotlin are
 detected without the Jackson Kotlin module present.
 
+Configuration classes can be
+https://kotlinlang.org/docs/reference/nested-classes.html[top level or nested but not inner]
+since the later requires a reference to the outer class.
+