diff --git a/README.md b/README.md
index fedba292..275586d4 100644
--- a/README.md
+++ b/README.md
@@ -249,14 +249,19 @@ Check the [tests](https://github.com/mockito/mockito-scala/blob/master/core/src/
 
 ## Default Answers
 We defined a new type `org.mockito.DefaultAnswer` which is used to configure the default behaviour of a mock when a non-stubbed invocation
-is made on it, the default behaviour is different to the Java version, instead of returning null for any non-primitive or non-final class,
-mockito-scala will return a "Smart Null", which is basically a mock of the type returned by the called method.
-The main advantage of this is that if the code tries to call any method on this mock, instead of failing with a NPE we will
-throw a different exception with a hint of the non-stubbed method call (including its params) that returned this Smart Null,
-this will make it much easier to find and fix a non-stubbed call
-
-Most of the Answers defined in `org.mockito.Answers` have it's counterpart as a `org.mockito.DefaultAnswer`, and on top of that
-we also provide `org.mockito.ReturnsEmptyValues` which will try its best to return an empty object for well known types, 
+is made on it.
+
+The object `org.mockito.DefaultAnswers` contains each one of the provided ones
+
+All the mocks created will use `ReturnsSmartNulls` by default, this is different to the Java version, which returns null for any non-primitive or non-final class.
+
+A "Smart Null", is nothing else than a mock of the type returned by the called method.
+The main advantage of doing that is that if the code tries to call any method on this mock, instead of failing with a NPE the mock will
+throw a different exception with a hint of the non-stubbed method that was called (including its params),
+this should make much easier the task of finding and fixing non-stubbed calls
+
+Most of the Answers defined in `org.mockito.Answers` have it's counterpart in `org.mockito.DefaultAnswers`, and on top of that
+we also provide `ReturnsEmptyValues` which will try its best to return an empty object for well known types, 
 i.e. `Nil` for `List`, `None` for `Option` etc.
 This DefaultAnswer is not part of the default behaviour as we think a SmartNull is better, to explain why, let's imagine we
 have the following code.
diff --git a/core/src/main/scala/org/mockito/DefaultAnswer.scala b/core/src/main/scala/org/mockito/DefaultAnswer.scala
index d7f15814..f24f0fb2 100644
--- a/core/src/main/scala/org/mockito/DefaultAnswer.scala
+++ b/core/src/main/scala/org/mockito/DefaultAnswer.scala
@@ -1,10 +1,8 @@
 package org.mockito
 
-import java.lang.reflect.Modifier.{isAbstract, isFinal}
+import java.lang.reflect.Modifier.isAbstract
 
 import org.mockito.exceptions.base.MockitoException
-import org.mockito.exceptions.verification.SmartNullPointerException
-import org.mockito.internal.util.ObjectMethodsGuru.isToStringMethod
 import org.mockito.invocation.InvocationOnMock
 import org.mockito.stubbing.Answer
 import org.mockito.Answers._
@@ -27,43 +25,18 @@ trait DefaultAnswer extends Answer[Any] with Function[InvocationOnMock, Option[A
 
 object DefaultAnswer {
   implicit val defaultAnswer: DefaultAnswer = ReturnsSmartNulls
-}
 
-object ReturnsDefaults extends DefaultAnswer {
-  override def apply(invocation: InvocationOnMock): Option[Any] = Option(RETURNS_DEFAULTS.answer(invocation))
+  def apply(from: Answer[_]): DefaultAnswer = new DecoratedAnswer(from)
 }
 
-object ReturnsSmartNulls extends DefaultAnswer {
-  override def apply(invocation: InvocationOnMock): Option[Any] = Option(RETURNS_DEFAULTS.answer(invocation)).orElse {
-    val returnType = invocation.getMethod.getReturnType
-
-    if (!returnType.isPrimitive && !isFinal(returnType.getModifiers))
-      Some(Mockito.mock(returnType, ThrowsSmartNullPointer(invocation)))
-    else
-      None
-  }
-
-  private case class ThrowsSmartNullPointer(unStubbedInvocation: InvocationOnMock) extends Answer[Any] {
-
-    override def answer(currentInvocation: InvocationOnMock): Any =
-      if (isToStringMethod(currentInvocation.getMethod))
-        s"""SmartNull returned by this un-stubbed method call on a mock:
-           |${unStubbedInvocation.toString}""".stripMargin
-      else
-        throw new SmartNullPointerException(
-          s"""You have a NullPointerException because this method call was *not* stubbed correctly:
-             |[$unStubbedInvocation] on the Mock [${unStubbedInvocation.getMock}]""".stripMargin)
-  }
-}
-
-object ReturnsDeepStubs extends DefaultAnswer {
-  override def apply(invocation: InvocationOnMock): Option[Any] = Option(RETURNS_DEEP_STUBS.answer(invocation))
-}
-
-object CallsRealMethods extends DefaultAnswer {
-  override def apply(invocation: InvocationOnMock): Option[Any] = Option(CALLS_REAL_METHODS.answer(invocation))
+class DecoratedAnswer(from: Answer[_]) extends DefaultAnswer {
+  override def apply(invocation: InvocationOnMock): Option[Any] = Option(from.answer(invocation))
 }
 
+object ReturnsDefaults   extends DecoratedAnswer(RETURNS_DEFAULTS)
+object ReturnsDeepStubs  extends DecoratedAnswer(RETURNS_DEEP_STUBS)
+object CallsRealMethods  extends DecoratedAnswer(CALLS_REAL_METHODS)
+object ReturnsSmartNulls extends DecoratedAnswer(RETURNS_SMART_NULLS)
 object ReturnsEmptyValues extends DefaultAnswer {
   private val javaEmptyValuesAndPrimitives = new ReturnsMoreEmptyValues
 
@@ -88,3 +61,14 @@ object ReturnsEmptyValues extends DefaultAnswer {
   override def apply(invocation: InvocationOnMock): Option[Any] =
     Option(javaEmptyValuesAndPrimitives.answer(invocation)).orElse(emptyValues.get(invocation.getMethod.getReturnType))
 }
+
+/**
+ * Simple object to act as an 'enum' of DefaultAnswers
+ */
+object DefaultAnswers {
+  val ReturnsDefaults: DefaultAnswer    = org.mockito.ReturnsDefaults
+  val ReturnsDeepStubs: DefaultAnswer   = org.mockito.ReturnsDeepStubs
+  val CallsRealMethods: DefaultAnswer   = org.mockito.CallsRealMethods
+  val ReturnsSmartNulls: DefaultAnswer  = org.mockito.ReturnsSmartNulls
+  val ReturnsEmptyValues: DefaultAnswer = org.mockito.ReturnsEmptyValues
+}
diff --git a/core/src/main/scala/org/mockito/IdiomaticMockito.scala b/core/src/main/scala/org/mockito/IdiomaticMockito.scala
index 864c3d6d..bc5f08f5 100644
--- a/core/src/main/scala/org/mockito/IdiomaticMockito.scala
+++ b/core/src/main/scala/org/mockito/IdiomaticMockito.scala
@@ -13,7 +13,7 @@ trait IdiomaticMockito extends MockCreator {
 
   override def mock[T <: AnyRef: ClassTag: TypeTag](mockSettings: MockSettings): T = MockitoSugar.mock[T](mockSettings)
 
-  override def mock[T <: AnyRef: ClassTag: TypeTag](defaultAnswer: Answer[_]): T = MockitoSugar.mock[T](defaultAnswer)
+  override def mock[T <: AnyRef: ClassTag: TypeTag](defaultAnswer: DefaultAnswer): T = MockitoSugar.mock[T](defaultAnswer)
 
   override def mock[T <: AnyRef: ClassTag: TypeTag](implicit defaultAnswer: DefaultAnswer): T =
     MockitoSugar.mock[T]
diff --git a/core/src/main/scala/org/mockito/MockitoAPI.scala b/core/src/main/scala/org/mockito/MockitoAPI.scala
index d5e5da2d..da7cb8f1 100644
--- a/core/src/main/scala/org/mockito/MockitoAPI.scala
+++ b/core/src/main/scala/org/mockito/MockitoAPI.scala
@@ -27,12 +27,20 @@ import scala.reflect.runtime.universe.TypeTag
 
 private[mockito] trait MockCreator {
   def mock[T <: AnyRef: ClassTag: TypeTag](implicit defaultAnswer: DefaultAnswer): T
-  def mock[T <: AnyRef: ClassTag: TypeTag](defaultAnswer: Answer[_]): T
+  def mock[T <: AnyRef: ClassTag: TypeTag](defaultAnswer: Answer[_]): T = mock[T](DefaultAnswer(defaultAnswer))
+  def mock[T <: AnyRef: ClassTag: TypeTag](defaultAnswer: DefaultAnswer): T
   def mock[T <: AnyRef: ClassTag: TypeTag](mockSettings: MockSettings): T
   def mock[T <: AnyRef: ClassTag: TypeTag](name: String)(implicit defaultAnswer: DefaultAnswer): T
 
   def spy[T](realObj: T): T
   def spyLambda[T <: AnyRef: ClassTag](realObj: T): T
+
+  /**
+    * Delegates to <code>Mockito.withSettings()</code>, it's only here to expose the full Mockito API
+    */
+  def withSettings(implicit defaultAnswer: DefaultAnswer): MockSettings =
+    Mockito.withSettings().defaultAnswer(defaultAnswer)
+
 }
 
 //noinspection MutatorLikeMethodIsParameterless
@@ -115,8 +123,8 @@ private[mockito] trait MockitoEnhancer extends MockCreator {
    * <code>verify(aMock).iHaveSomeDefaultArguments("I'm not gonna pass the second argument", "default value")</code>
    * as the value for the second parameter would have been null...
    */
-  override def mock[T <: AnyRef: ClassTag: TypeTag](defaultAnswer: Answer[_]): T =
-    mock(withSettings(defaultAnswer.lift))
+  override def mock[T <: AnyRef: ClassTag: TypeTag](defaultAnswer: DefaultAnswer): T =
+    mock(withSettings(defaultAnswer))
 
   /**
    * Delegates to <code>Mockito.mock(type: Class[T], mockSettings: MockSettings)</code>
@@ -208,12 +216,6 @@ private[mockito] trait MockitoEnhancer extends MockCreator {
    */
   def mockingDetails(toInspect: AnyRef): MockingDetails = Mockito.mockingDetails(toInspect)
 
-  /**
-   * Delegates to <code>Mockito.withSettings()</code>, it's only here to expose the full Mockito API
-   */
-  def withSettings(implicit defaultAnswer: DefaultAnswer): MockSettings =
-    Mockito.withSettings().defaultAnswer(defaultAnswer)
-
   /**
    * Delegates to <code>Mockito.verifyNoMoreInteractions(Object... mocks)</code>, but ignores the default stubs that
    * deal with default argument values
diff --git a/core/src/main/scala/org/mockito/MockitoScalaSession.scala b/core/src/main/scala/org/mockito/MockitoScalaSession.scala
index 585ce090..c7e39431 100644
--- a/core/src/main/scala/org/mockito/MockitoScalaSession.scala
+++ b/core/src/main/scala/org/mockito/MockitoScalaSession.scala
@@ -1,7 +1,8 @@
 package org.mockito
 
-import org.mockito.MockitoScalaSession.UnexpectedInvocationsMockListener
-import org.mockito.exceptions.misusing.UnexpectedInvocationException
+import org.mockito.MockitoScalaSession.{MockitoScalaSessionListener, UnexpectedInvocations}
+import org.mockito.exceptions.misusing.{UnexpectedInvocationException, UnnecessaryStubbingException}
+import org.mockito.internal.stubbing.StubbedInvocationMatcher
 import org.mockito.invocation.{DescribedInvocation, Invocation, Location}
 import org.mockito.listeners.MockCreationListener
 import org.mockito.mock.MockCreationSettings
@@ -13,7 +14,7 @@ import scala.collection.mutable
 import scala.collection.JavaConverters._
 
 class MockitoScalaSession(name: String, strictness: Strictness, logger: MockitoSessionLogger) {
-  private val listener       = new UnexpectedInvocationsMockListener
+  private val listener       = new MockitoScalaSessionListener
   private val mockitoSession = Mockito.mockitoSession().name(name).logger(logger).strictness(strictness).startMocking()
 
   Mockito.framework().addListener(listener)
@@ -22,16 +23,17 @@ class MockitoScalaSession(name: String, strictness: Strictness, logger: MockitoS
     try {
       t.fold {
         mockitoSession.finishMocking()
-        listener.reportUnStubbedCalls().reportUnexpectedInvocations()
+        listener.reportIssues().foreach(_.report())
       } {
         case e: NullPointerException =>
           mockitoSession.finishMocking(e)
-          val unStubbedCalls = listener.reportUnStubbedCalls()
-          if (unStubbedCalls.nonEmpty)
-            throw new UnexpectedInvocationException(s"""A NullPointerException was thrown, check if maybe related to
-               |$unStubbedCalls""".stripMargin,
-                                                    e)
-          else throw e
+          listener.reportIssues().foreach {
+            case unStubbedCalls: UnexpectedInvocations if unStubbedCalls.nonEmpty =>
+              throw new UnexpectedInvocationException(s"""A NullPointerException was thrown, check if maybe related to
+                   |$unStubbedCalls""".stripMargin,
+                                                      e)
+            case _ => throw e
+          }
         case other =>
           mockitoSession.finishMocking(other)
           throw other
@@ -63,7 +65,11 @@ object MockitoScalaSession {
     override def getLocation: Location = SyntheticLocation
   }
 
-  case class UnexpectedInvocations(invocations: Set[Invocation]) {
+  trait Reporter {
+    def report(): Unit
+  }
+
+  case class UnexpectedInvocations(invocations: Set[Invocation]) extends Reporter {
     def nonEmpty: Boolean = invocations.nonEmpty
 
     override def toString: String =
@@ -80,25 +86,59 @@ object MockitoScalaSession {
            |Please make sure you aren't missing any stubbing or that your code actually does what you want""".stripMargin
       } else "No unexpected invocations found"
 
-    def reportUnexpectedInvocations(): Unit =
-      if (nonEmpty) throw new UnexpectedInvocationException(toString)
+    def report(): Unit = if (nonEmpty) throw new UnexpectedInvocationException(toString)
   }
 
-  class UnexpectedInvocationsMockListener extends MockCreationListener {
-    def reportUnStubbedCalls(): UnexpectedInvocations =
-      UnexpectedInvocations(
-        mocks
-          .map(MockitoSugar.mockingDetails)
-          .flatMap(_.getInvocations.asScala)
-          .filter(_.stubInfo() == null)
-          .filterNot(_.isVerified)
-          .filterNot(_.getMethod.getName.contains("$default$"))
-          .toSet
+  case class UnusedStubbings(stubbings: Set[StubbedInvocationMatcher]) extends Reporter {
+    def nonEmpty: Boolean = stubbings.nonEmpty
+
+    override def toString: String =
+      if (nonEmpty) {
+        val locations = stubbings.zipWithIndex
+          .map {
+            case (stubbing, idx) => s"${idx + 1}. $stubbing ${stubbing.getLocation}"
+          }
+          .mkString("\n")
+        s"""Unnecessary stubbings detected.
+           |
+           |Clean & maintainable test code requires zero unnecessary code.
+           |Following stubbings are unnecessary (click to navigate to relevant line of code):
+           |$locations
+           |Please remove unnecessary stubbings or use 'lenient' strictness. More info: javadoc for UnnecessaryStubbingException class.""".stripMargin
+      } else "No unexpected invocations found"
+
+    def report(): Unit = if (nonEmpty) throw new UnnecessaryStubbingException(toString)
+  }
+
+  class MockitoScalaSessionListener extends MockCreationListener {
+    def reportIssues(): Seq[Reporter] = {
+      val mockDetails = mocks.toSet.map(MockitoSugar.mockingDetails)
+
+      val stubbings = mockDetails
+        .flatMap(_.getStubbings.asScala)
+        .collect {
+          case s: StubbedInvocationMatcher => s
+        }
+
+      val invocations = mockDetails.flatMap(_.getInvocations.asScala)
+
+      val unexpectedInvocations = invocations
+        .filterNot(_.isVerified)
+        .filterNot(_.getMethod.getName.contains("$default$"))
+        .filterNot(i => stubbings.exists(_.matches(i)))
+
+      val unusedStubbings = stubbings.filterNot(sm => invocations.exists(sm.matches)).filter(!_.wasUsed())
+
+      Seq(
+        UnexpectedInvocations(unexpectedInvocations),
+        UnusedStubbings(unusedStubbings)
       )
+    }
 
     private val mocks = mutable.Set.empty[AnyRef]
 
-    override def onMockCreated(mock: AnyRef, settings: MockCreationSettings[_]): Unit = mocks += mock
+    override def onMockCreated(mock: AnyRef, settings: MockCreationSettings[_]): Unit =
+      if (!settings.isLenient) mocks += mock
   }
 }
 
diff --git a/core/src/main/scala/org/mockito/integrations/scalatest/ResetMocksAfterEachTest.scala b/core/src/main/scala/org/mockito/integrations/scalatest/ResetMocksAfterEachTest.scala
index e83a8413..8d6962e0 100644
--- a/core/src/main/scala/org/mockito/integrations/scalatest/ResetMocksAfterEachTest.scala
+++ b/core/src/main/scala/org/mockito/integrations/scalatest/ResetMocksAfterEachTest.scala
@@ -3,7 +3,6 @@ package org.mockito.integrations.scalatest
 import java.util.concurrent.ConcurrentHashMap
 
 import org.mockito.{DefaultAnswer, MockCreator, MockitoSugar, MockSettings}
-import org.mockito.stubbing.Answer
 import org.scalatest.{Outcome, TestSuite}
 
 import scala.collection.JavaConverters._
@@ -37,7 +36,7 @@ trait ResetMocksAfterEachTest extends TestSuite with MockCreator { self: MockCre
   abstract override def mock[T <: AnyRef: ClassTag: TypeTag](implicit defaultAnswer: DefaultAnswer): T =
     addMock(super.mock[T])
 
-  abstract override def mock[T <: AnyRef: ClassTag: TypeTag](defaultAnswer: Answer[_]): T =
+  abstract override def mock[T <: AnyRef: ClassTag: TypeTag](defaultAnswer: DefaultAnswer): T =
     addMock(super.mock[T](defaultAnswer))
 
   abstract override def mock[T <: AnyRef: ClassTag: TypeTag](mockSettings: MockSettings): T =
diff --git a/core/src/main/scala/org/mockito/package.scala b/core/src/main/scala/org/mockito/package.scala
index ba0899dd..c337d97a 100644
--- a/core/src/main/scala/org/mockito/package.scala
+++ b/core/src/main/scala/org/mockito/package.scala
@@ -112,10 +112,4 @@ package object mockito {
           i.getArgument[P9](9),
           i.getArgument[P10](10)
       ))
-
-  implicit class AnswerOps[T](val a: Answer[T]) extends AnyVal {
-    def lift: DefaultAnswer = new DefaultAnswer {
-      override def apply(invocation: InvocationOnMock): Option[Any] = Option(a.answer(invocation))
-    }
-  }
 }
diff --git a/core/src/test/scala-2.11/org/mockito/MockitoSugarTest_211.scala b/core/src/test/scala-2.11/org/mockito/MockitoSugarTest_211.scala
index bfd566fe..4182f7c2 100644
--- a/core/src/test/scala-2.11/org/mockito/MockitoSugarTest_211.scala
+++ b/core/src/test/scala-2.11/org/mockito/MockitoSugarTest_211.scala
@@ -17,7 +17,7 @@ class MockitoSugarTest_211 extends WordSpec with MockitoSugar with scalatest.Mat
 
       aMock.traitMethod() shouldBe 69
 
-      verify(aMock).traitMethod(0, null)
+      verify(aMock).traitMethod(0, "")
     }
   }
 }
diff --git a/core/src/test/scala/org/mockito/DefaultAnswerTest.scala b/core/src/test/scala/org/mockito/DefaultAnswerTest.scala
index 39ddaff5..86766b8a 100644
--- a/core/src/test/scala/org/mockito/DefaultAnswerTest.scala
+++ b/core/src/test/scala/org/mockito/DefaultAnswerTest.scala
@@ -95,13 +95,11 @@ class DefaultAnswerTest
 
       smartNull should not be null
 
-      val throwable: SmartNullPointerException = the[SmartNullPointerException] thrownBy {
+      val throwable = the[SmartNullPointerException] thrownBy {
         smartNull.callMeMaybe()
       }
 
-      throwable.getMessage shouldBe
-      s"""You have a NullPointerException because this method call was *not* stubbed correctly:
-           |[foo.userClass(42);] on the Mock [$aMock]""".stripMargin
+      throwable.getMessage should include("You have a NullPointerException here:")
     }
 
     "return a smart standard monad" in {
@@ -113,9 +111,7 @@ class DefaultAnswerTest
         smartNull.isEmpty
       }
 
-      throwable.getMessage shouldBe
-      s"""You have a NullPointerException because this method call was *not* stubbed correctly:
-           |[foo.returnsList();] on the Mock [$aMock]""".stripMargin
+      throwable.getMessage should include("You have a NullPointerException here:")
     }
 
     "return a default value for primitives" in {
@@ -138,7 +134,7 @@ class DefaultAnswerTest
 
   "ReturnsEmptyValues" should {
     "return a default value for primitives" in {
-      val primitives = mock[Primitives](ReturnsEmptyValues)
+      val primitives = mock[Primitives](DefaultAnswers.ReturnsEmptyValues)
 
       primitives.barByte shouldBe 0.toByte
       primitives.barBoolean shouldBe false
@@ -151,7 +147,7 @@ class DefaultAnswerTest
     }
 
     "return the empty values for known classes" in {
-      val aMock = mock[KnownTypes](ReturnsEmptyValues)
+      val aMock = mock[KnownTypes](DefaultAnswers.ReturnsEmptyValues)
 
       aMock.returnsOption shouldBe None
       aMock.returnsList shouldBe List.empty
diff --git a/core/src/test/scala/org/mockito/MockitoScalaSessionTest.scala b/core/src/test/scala/org/mockito/MockitoScalaSessionTest.scala
index dda6abc5..c6f7fdb0 100644
--- a/core/src/test/scala/org/mockito/MockitoScalaSessionTest.scala
+++ b/core/src/test/scala/org/mockito/MockitoScalaSessionTest.scala
@@ -3,10 +3,10 @@ package org.mockito
 import org.scalatest
 import org.mockito.exceptions.misusing.{PotentialStubbingProblem, UnexpectedInvocationException, UnnecessaryStubbingException}
 import org.mockito.exceptions.verification.SmartNullPointerException
-import org.scalatest.WordSpec
+import org.scalatest.{OptionValues, WordSpec}
 
 //noinspection RedundantDefaultArgument
-class MockitoScalaSessionTest extends WordSpec with IdiomaticMockito with scalatest.Matchers {
+class MockitoScalaSessionTest extends WordSpec with IdiomaticMockito with scalatest.Matchers with OptionValues {
 
   class Foo {
     def bar(a: String) = "bar"
@@ -19,11 +19,17 @@ class MockitoScalaSessionTest extends WordSpec with IdiomaticMockito with scalat
   }
 
   class Bar {
-    def callMeMaybe: Option[Boolean] = None
+    def callMeMaybe: Baz = ???
+    def dontCallMe: Baz  = ???
+  }
+
+  class Baz {
+    def callMe: Option[String]     = ???
+    def dontCallMe: Option[String] = ???
   }
 
   final class BarFinal {
-    def callMeMaybe: Option[Boolean] = None
+    def callMeMaybe: Option[Boolean] = ???
   }
 
   "MockitoScalaSession" should {
@@ -62,7 +68,7 @@ class MockitoScalaSessionTest extends WordSpec with IdiomaticMockito with scalat
         }
       }
 
-      thrown.getMessage should startWith("A NullPointerException was thrown, check if maybe related to")
+      thrown.getMessage should startWith("Unexpected invocations found")
     }
 
     "check SmartNull" in {
@@ -74,7 +80,7 @@ class MockitoScalaSessionTest extends WordSpec with IdiomaticMockito with scalat
         }
       }
 
-      thrown.getMessage should startWith("You have a NullPointerException because this method call was *not* stubbed correctly")
+      thrown.getMessage should include("You have a NullPointerException here:")
     }
 
     "check incorrect stubs after the expected one was called on a final class" in {
@@ -168,6 +174,67 @@ class MockitoScalaSessionTest extends WordSpec with IdiomaticMockito with scalat
         }
       }
     }
+
+    "don't check unused stubs for lenient mocks" in {
+      MockitoScalaSession().run {
+        val foo = mock[Foo](withSettings.lenient())
+
+        foo.bar("pepe") shouldReturn "mocked"
+
+        foo.bar("pepe")
+
+        foo.bar("paco")
+      }
+    }
+
+    "work with nested deep stubs" in {
+      MockitoScalaSession().run {
+        val foo = mock[Foo](ReturnsDeepStubs)
+
+        foo.userClass.callMeMaybe.callMe shouldReturn Some("my number")
+
+        foo.userClass.callMeMaybe.callMe.value shouldBe "my number"
+      }
+    }
+
+    "not fail if a final deep stub is called in a non stubbed method" in {
+      MockitoScalaSession().run {
+        val foo = mock[Foo](ReturnsDeepStubs)
+
+        foo.userClass.callMeMaybe.callMe shouldReturn Some("my number")
+
+        foo.userClass.callMeMaybe.callMe.value shouldBe "my number"
+
+        foo.userClass.callMeMaybe.dontCallMe
+
+      }
+    }
+
+    "not fail if a nested deep stub is called in a non stubbed method" in {
+      MockitoScalaSession().run {
+        val foo = mock[Foo](ReturnsDeepStubs)
+
+        foo.userClass.callMeMaybe.callMe shouldReturn Some("my number")
+
+        foo.userClass.callMeMaybe.callMe.value shouldBe "my number"
+
+        foo.userClass.dontCallMe
+
+      }
+    }
+
+    "fail if a nested deep stub is stubbed but not used" in {
+      val thrown = the[UnnecessaryStubbingException] thrownBy {
+        MockitoScalaSession().run {
+          val foo = mock[Foo](ReturnsDeepStubs)
+
+          foo.userClass.callMeMaybe.callMe shouldReturn Some("my number")
+
+        }
+      }
+
+      thrown.getMessage should startWith("Unnecessary stubbings detected")
+    }
   }
 
 }
diff --git a/core/src/test/scala/org/mockito/MockitoSugarTest.scala b/core/src/test/scala/org/mockito/MockitoSugarTest.scala
index 99e5c102..373da005 100644
--- a/core/src/test/scala/org/mockito/MockitoSugarTest.scala
+++ b/core/src/test/scala/org/mockito/MockitoSugarTest.scala
@@ -107,7 +107,7 @@ class MockitoSugarTest extends WordSpec with MockitoSugar with scalatest.Matcher
       when(aMock.iStartWithByNameArgs("arg1", "arg2")) thenReturn "mocked!"
 
       aMock.iStartWithByNameArgs("arg1", "arg2") shouldBe "mocked!"
-      aMock.iStartWithByNameArgs("arg111", "arg2") shouldBe null
+      aMock.iStartWithByNameArgs("arg111", "arg2") shouldBe ""
 
       verify(aMock).iStartWithByNameArgs("arg1", "arg2")
       verify(aMock).iStartWithByNameArgs("arg111", "arg2")
@@ -119,7 +119,7 @@ class MockitoSugarTest extends WordSpec with MockitoSugar with scalatest.Matcher
       when(aMock.iHavePrimitiveByNameArgs(1, "arg2")) thenReturn "mocked!"
 
       aMock.iHavePrimitiveByNameArgs(1, "arg2") shouldBe "mocked!"
-      aMock.iHavePrimitiveByNameArgs(2, "arg2") shouldBe null
+      aMock.iHavePrimitiveByNameArgs(2, "arg2") shouldBe ""
 
       verify(aMock).iHavePrimitiveByNameArgs(1, "arg2")
       verify(aMock).iHavePrimitiveByNameArgs(2, "arg2")
@@ -131,7 +131,7 @@ class MockitoSugarTest extends WordSpec with MockitoSugar with scalatest.Matcher
       when(aMock.iHaveFunction0Args(eqTo("arg1"), function0("arg2"))) thenReturn "mocked!"
 
       aMock.iHaveFunction0Args("arg1", () => "arg2") shouldBe "mocked!"
-      aMock.iHaveFunction0Args("arg1", () => "arg3") shouldBe null
+      aMock.iHaveFunction0Args("arg1", () => "arg3") shouldBe ""
 
       verify(aMock).iHaveFunction0Args(eqTo("arg1"), function0("arg2"))
       verify(aMock).iHaveFunction0Args(eqTo("arg1"), function0("arg3"))
@@ -156,8 +156,8 @@ class MockitoSugarTest extends WordSpec with MockitoSugar with scalatest.Matcher
 
       reset(aMock)
 
-      aMock.bar shouldBe null
-      aMock.iHavePrimitiveByNameArgs(1, "arg2") shouldBe null
+      aMock.bar shouldBe ""
+      aMock.iHavePrimitiveByNameArgs(1, "arg2") shouldBe ""
 
       //to verify the reset mock handler still handles by-name params
       when(aMock.iHavePrimitiveByNameArgs(1, "arg2")) thenReturn "mocked!"