diff --git a/modules/benchmark/src/main/scala/eu/timepit/refined/benchmark/PosIntBenchmark.scala b/modules/benchmark/src/main/scala/eu/timepit/refined/benchmark/PosIntBenchmark.scala
new file mode 100644
index 000000000..305a77c0a
--- /dev/null
+++ b/modules/benchmark/src/main/scala/eu/timepit/refined/benchmark/PosIntBenchmark.scala
@@ -0,0 +1,14 @@
+package eu.timepit.refined.benchmark
+
+import eu.timepit.refined.types.numeric.PosInt
+import java.util.concurrent.TimeUnit
+import org.openjdk.jmh.annotations.{Benchmark, BenchmarkMode, Mode, OutputTimeUnit}
+
+@BenchmarkMode(Array(Mode.AverageTime))
+class PosIntBenchmark {
+
+  @Benchmark
+  @OutputTimeUnit(TimeUnit.NANOSECONDS)
+  def unsafeFrom_1: Any =
+    PosInt.unsafeFrom(1)
+}
diff --git a/modules/core/shared/src/main/scala/eu/timepit/refined/api/RefinedType.scala b/modules/core/shared/src/main/scala/eu/timepit/refined/api/RefinedType.scala
index d58dd0850..5c8bea339 100644
--- a/modules/core/shared/src/main/scala/eu/timepit/refined/api/RefinedType.scala
+++ b/modules/core/shared/src/main/scala/eu/timepit/refined/api/RefinedType.scala
@@ -22,12 +22,15 @@ trait RefinedType[FTP] extends Serializable {
 
   final def refine(t: T): Either[String, FTP] = {
     val res = validate.validate(t)
-    if (res.isPassed) Right(alias(refType.unsafeWrap(t)))
+    if (res.isPassed) Right(refType.unsafeWrap(t).asInstanceOf[FTP])
     else Left(validate.showResult(t, res))
   }
 
-  final def unsafeRefine(t: T): FTP =
-    refine(t).fold(err => throw new IllegalArgumentException(err), identity)
+  final def unsafeRefine(t: T): FTP = {
+    val res = validate.validate(t)
+    if (res.isPassed) refType.unsafeWrap(t).asInstanceOf[FTP]
+    else throw new IllegalArgumentException(validate.showResult(t, res))
+  }
 }
 
 object RefinedType {
diff --git a/notes/0.9.1.markdown b/notes/0.9.1.markdown
index bc1f8e765..2cc2f4313 100644
--- a/notes/0.9.1.markdown
+++ b/notes/0.9.1.markdown
@@ -6,8 +6,14 @@
   if a `String` is a parsable `Byte`, `Short`, or `Float`.
   ([#492][#492] by [@sh0hei][@sh0hei])
 
+### Changes
+
+* Improve performance of `RefinedType#unsafeFrom`.
+  ([#499][#499] by [@fthomas][@fthomas])
+
 [#486]: https://github.com/fthomas/refined/pull/486
 [#492]: https://github.com/fthomas/refined/pull/492
+[#499]: https://github.com/fthomas/refined/pull/499
 
 [@fthomas]: https://github.com/fthomas
 [@sh0hei]: https://github.com/sh0hei
diff --git a/project/plugin-jmh.sbt b/project/plugin-jmh.sbt
index cd0614272..be94ef136 100644
--- a/project/plugin-jmh.sbt
+++ b/project/plugin-jmh.sbt
@@ -1 +1 @@
-addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.3.0")
+addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.3.3")