diff --git a/jvm/src/test/scala/msgpack4z/Java06Spec.scala b/jvm/src/test/scala/msgpack4z/Java06Spec.scala
index 88c64aae..ce8a854a 100644
--- a/jvm/src/test/scala/msgpack4z/Java06Spec.scala
+++ b/jvm/src/test/scala/msgpack4z/Java06Spec.scala
@@ -1,6 +1,6 @@
 package msgpack4z
 
-trait Java06Spec { _: SpecBase =>
+trait Java06Spec { self: SpecBase =>
   override protected[this] def packer() = Msgpack06.defaultPacker()
   override protected[this] def unpacker(bytes: Array[Byte]) = Msgpack06.defaultUnpacker(bytes)
 }
diff --git a/src/test/scala/msgpack4z/IntSpec.scala b/src/test/scala/msgpack4z/IntSpec.scala
index d094ea70..db45de81 100644
--- a/src/test/scala/msgpack4z/IntSpec.scala
+++ b/src/test/scala/msgpack4z/IntSpec.scala
@@ -5,7 +5,7 @@ import scalaprops.Property.forAll
 abstract class IntSpec extends SpecBase {
   override def param = super.param.copy(minSuccessful = 200)
 
-  val int8 = forAll { x: Byte =>
+  val int8 = forAll { (x: Byte) =>
     def u = unpacker(Array[Byte](msgpack4z.Code.INT8, x))
     assert(u.unpackByte() == x)
     assert(u.unpackShort() == x)
@@ -16,7 +16,7 @@ abstract class IntSpec extends SpecBase {
     true
   }
 
-  val int16 = forAll { x: Short =>
+  val int16 = forAll { (x: Short) =>
     def u = {
       val buf = MsgOutBuffer.create()
       buf.writeByteAndShort(Code.INT16, x)
@@ -37,7 +37,7 @@ abstract class IntSpec extends SpecBase {
     true
   }
 
-  val int32 = forAll { x: Int =>
+  val int32 = forAll { (x: Int) =>
     def u = {
       val buf = MsgOutBuffer.create()
       buf.writeByteAndInt(Code.INT32, x)
@@ -64,7 +64,7 @@ abstract class IntSpec extends SpecBase {
     true
   }
 
-  val int64 = forAll { x: Long =>
+  val int64 = forAll { (x: Long) =>
     def u = {
       val buf = MsgOutBuffer.create()
       buf.writeByteAndLong(Code.INT64, x)
diff --git a/src/test/scala/msgpack4z/Spec.scala b/src/test/scala/msgpack4z/Spec.scala
index fa8b3bda..fdf6b3a0 100644
--- a/src/test/scala/msgpack4z/Spec.scala
+++ b/src/test/scala/msgpack4z/Spec.scala
@@ -1,6 +1,6 @@
 package msgpack4z
 
-trait NativeSpec { _: SpecBase =>
+trait NativeSpec { self: SpecBase =>
   override protected[this] def packer() = MsgOutBuffer.create()
   override protected[this] def unpacker(bytes: Array[Byte]) = MsgInBuffer(bytes)
 }
diff --git a/src/test/scala/msgpack4z/SpecBase.scala b/src/test/scala/msgpack4z/SpecBase.scala
index 23aede12..9c4efe55 100644
--- a/src/test/scala/msgpack4z/SpecBase.scala
+++ b/src/test/scala/msgpack4z/SpecBase.scala
@@ -25,7 +25,7 @@ abstract class SpecBase extends Scalaprops {
     Gen.alphaNumString
 
   final def checkRoundTripBytes[A](checkHashCode: Boolean)(implicit A: MsgpackCodec[A], G: Gen[A], E: Equal[A]): Property =
-    Property.forAll { a: A =>
+    Property.forAll { (a: A) =>
       try {
         A.roundtripz(a, packer(), unpacker _) match {
           case None =>
diff --git a/src/test/scala/msgpack4z/UnionSpec.scala b/src/test/scala/msgpack4z/UnionSpec.scala
index fbb70c01..027f2688 100644
--- a/src/test/scala/msgpack4z/UnionSpec.scala
+++ b/src/test/scala/msgpack4z/UnionSpec.scala
@@ -5,13 +5,13 @@ import scalaprops._
 import scalaz._
 
 abstract class UnionSpec(unionGen0: Gen[MsgpackUnion] = UnionGen.unionGen) extends SpecBase {
-  private implicit def unionGen = unionGen0
+  private implicit def unionGen: Gen[MsgpackUnion] = unionGen0
 
   private def supportExtType: Boolean = unionGen == UnionGen.unionGen
 
   val union = checkLaw(MsgpackUnion.codecInstance, unionGen)
 
-  val `equals hashCode` = Property.forAll { a: MsgpackUnion =>
+  val `equals hashCode` = Property.forAll { (a: MsgpackUnion) =>
     val M = MsgpackCodec[MsgpackUnion]
     val bytes = M.toBytes(a, packer())
     M.unpackAndClose(unpacker(bytes)) match {
@@ -23,13 +23,13 @@ abstract class UnionSpec(unionGen0: Gen[MsgpackUnion] = UnionGen.unionGen) exten
     }
   }.toProperties((), Param.minSuccessful(10000))
 
-  val `MsgpackLong and MsgpackULong` = Property.forAll { a: Long =>
+  val `MsgpackLong and MsgpackULong` = Property.forAll { (a: Long) =>
     val x = MsgpackLong(a)
     val y = MsgpackULong(java.math.BigInteger.valueOf(a))
     (y == x) && (x == y) && (x.hashCode == y.hashCode)
   }
 
-  val `MsgpackLong pack/unpack MsgpackLong` = Property.forAll { a: Long =>
+  val `MsgpackLong pack/unpack MsgpackLong` = Property.forAll { (a: Long) =>
     val M = MsgpackCodec[MsgpackUnion]
     val b = MsgpackLong(a)
     val c = M.toBytes(b, packer())
@@ -41,7 +41,7 @@ abstract class UnionSpec(unionGen0: Gen[MsgpackUnion] = UnionGen.unionGen) exten
     }
   }
 
-  val extEqualsHashcode = Property.forAllG(UnionGen.extGen) { e1: MsgpackExt =>
+  val extEqualsHashcode = Property.forAllG(UnionGen.extGen) { (e1: MsgpackExt) =>
     val e2 = e1.copy()
     (e1 ne e2) && (e1 == e2) && (e1.## == e2.##)
   }
@@ -106,7 +106,7 @@ abstract class UnionSpec(unionGen0: Gen[MsgpackUnion] = UnionGen.unionGen) exten
     } else true
   }
 
-  val `map imap` = Property.forAll { a: Map[MsgpackUnion, MsgpackUnion] =>
+  val `map imap` = Property.forAll { (a: Map[MsgpackUnion, MsgpackUnion]) =>
     val b = MsgpackUnion.map(a)
     val c = IMap.fromList(a.toList)
     val d = MsgpackUnion.imap(c)