diff --git a/akka-stream-tests/src/test/scala/akka/stream/io/FileSourceSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/io/FileSourceSpec.scala
index 10f9978e7f..42fe540583 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/io/FileSourceSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/io/FileSourceSpec.scala
@@ -19,11 +19,9 @@ import akka.stream.testkit.Utils._
 import akka.stream.testkit.scaladsl.StreamTestKit._
 import akka.stream.testkit._
 import akka.stream.testkit.scaladsl.TestSink
-import akka.testkit.TestDuration
 import akka.util.ByteString
 import com.google.common.jimfs.{ Configuration, Jimfs }
 
-import scala.concurrent.Await
 import scala.concurrent.duration._
 
 object FileSourceSpec {
@@ -59,6 +57,8 @@ class FileSourceSpec extends StreamSpec(UnboundedMailboxConfig) {
     f
   }
 
+  val directoryInsteadOfFile = Files.createTempDirectory(fs.getPath("/"), "directory-instead-of-file")
+
   val LinesCount = 2000 + new Random().nextInt(300)
 
   val manyLines = {
@@ -116,7 +116,7 @@ class FileSourceSpec extends StreamSpec(UnboundedMailboxConfig) {
       p.request(1)
       p.expectNext().utf8String should ===(TestText.splitAt(chunkSize)._1)
       mat.shutdown()
-      Await.result(future, 3.seconds) === createSuccessful(chunkSize)
+      future.futureValue === createSuccessful(chunkSize)
     }
 
     "read partial contents from a file" in assertAllStagesStopped {
@@ -154,7 +154,7 @@ class FileSourceSpec extends StreamSpec(UnboundedMailboxConfig) {
       p.request(1)
       p.expectNext().utf8String should ===(TestText.splitAt(chunkSize)._1)
       p.cancel()
-      Await.result(future, 3.seconds) === createSuccessful(chunkSize)
+      future.futureValue === createSuccessful(chunkSize)
     }
 
     "complete only when all contents of a file have been signalled" in assertAllStagesStopped {
@@ -200,7 +200,20 @@ class FileSourceSpec extends StreamSpec(UnboundedMailboxConfig) {
       val error = c.expectError()
       error shouldBe a[NoSuchFileException]
 
-      Await.result(r, 3.seconds.dilated).status.isFailure shouldBe true
+      r.futureValue.status.isFailure shouldBe true
+    }
+
+    "onError with failure and return a failed IOResult when trying to read from a directory instead of a file" in assertAllStagesStopped {
+      val (r, p) = FileIO.fromPath(directoryInsteadOfFile).toMat(Sink.asPublisher(false))(Keep.both).run()
+      val c = TestSubscriber.manualProbe[ByteString]()
+      p.subscribe(c)
+
+      c.expectSubscription()
+
+      val error = c.expectError()
+      error shouldBe an[IllegalArgumentException]
+
+      r.futureValue.status.isFailure shouldBe true
     }
 
     List(
@@ -216,8 +229,7 @@ class FileSourceSpec extends StreamSpec(UnboundedMailboxConfig) {
 
           val f = s.runWith(Sink.fold(0) { case (acc, l) ⇒ acc + l.utf8String.count(_ == '\n') })
 
-          val lineCount = Await.result(f, 3.seconds)
-          lineCount should ===(LinesCount)
+          f.futureValue should ===(LinesCount)
         }
       }
 
diff --git a/akka-stream/src/main/scala/akka/stream/impl/io/IOSources.scala b/akka-stream/src/main/scala/akka/stream/impl/io/IOSources.scala
index b2e5843d62..63ac15b192 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/io/IOSources.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/io/IOSources.scala
@@ -73,7 +73,7 @@ private[akka] final class FileSource(path: Path, chunkSize: Int, startPosition:
           // this is a bit weird but required to keep existing semantics
           if (!Files.exists(path)) throw new NoSuchFileException(path.toString)
 
-          require(Files.isRegularFile(path), s"Path '$path' is not a regular file")
+          require(!Files.isDirectory(path), s"Path '$path' is a directory")
           require(Files.isReadable(path), s"Missing read permission for '$path'")
 
           channel = FileChannel.open(path, StandardOpenOption.READ)