diff --git a/akka-testkit/src/test/scala/akka/testkit/metrics/reporter/PrettyDurationSpec.scala b/akka-testkit/src/test/scala/akka/testkit/metrics/reporter/PrettyDurationSpec.scala
index 8832476a3a..1462822447 100644
--- a/akka-testkit/src/test/scala/akka/testkit/metrics/reporter/PrettyDurationSpec.scala
+++ b/akka-testkit/src/test/scala/akka/testkit/metrics/reporter/PrettyDurationSpec.scala
@@ -4,6 +4,7 @@
 package akka.testkit.metrics.reporter
 
 import org.scalatest.{ Matchers, FlatSpec }
+import java.util.Locale
 
 class PrettyDurationSpec extends FlatSpec with Matchers {
 
@@ -12,21 +13,22 @@ class PrettyDurationSpec extends FlatSpec with Matchers {
   import concurrent.duration._
   import PrettyDuration._
 
-  val cases =
-    9.nanos -> "9.000 ns" ::
-      95.nanos -> "95.00 ns" ::
-      999.nanos -> "999.0 ns" ::
-      1000.nanos -> "1.000 μs" ::
-      9500.nanos -> "9.500 μs" ::
-      9500.micros -> "9.500 ms" ::
-      9500.millis -> "9.500 s" ::
-      95.seconds -> "1.583 min" ::
-      95.minutes -> "1.583 h" ::
-      95.hours -> "3.958 d" ::
+  val cases: Seq[(Duration, (Float, Int, String))] =
+    9.nanos -> ((9.000f, 3, "ns")) ::
+      95.nanos -> ((95.00f, 2, "ns")) ::
+      999.nanos -> ((999.0f, 1, "ns")) ::
+      1000.nanos -> ((1.000f, 3, "μs")) ::
+      9500.nanos -> ((9.500f, 3, "μs")) ::
+      9500.micros -> ((9.500f, 3, "ms")) ::
+      9500.millis -> ((9.500f, 3, "s")) ::
+      95.seconds -> ((1.583f, 3, "min")) ::
+      95.minutes -> ((1.583f, 3, "h")) ::
+      95.hours -> ((3.958f, 3, "d")) ::
       Nil
 
   cases foreach {
-    case (d, prettyString) ⇒
+    case (d, (expectedValue, precision, unit)) ⇒
+      val prettyString = s"%.${precision}f $unit" formatLocal (Locale.getDefault, expectedValue)
       it should s"print $d seconds as $prettyString" in {
         d.pretty should equal(prettyString)
       }