diff --git a/akka-http-tests/src/test/scala/akka/http/scaladsl/coding/GzipSpec.scala b/akka-http-tests/src/test/scala/akka/http/scaladsl/coding/GzipSpec.scala
index f95dad83d9..914f834f31 100644
--- a/akka-http-tests/src/test/scala/akka/http/scaladsl/coding/GzipSpec.scala
+++ b/akka-http-tests/src/test/scala/akka/http/scaladsl/coding/GzipSpec.scala
@@ -22,14 +22,12 @@ class GzipSpec extends CoderSpec {
 
   override def extraTests(): Unit = {
     "decode concatenated compressions" in {
-      pending // FIXME: unbreak
       ourDecode(Seq(encode("Hello, "), encode("dear "), encode("User!")).join) should readAs("Hello, dear User!")
     }
     "provide a better compression ratio than the standard Gzip/Gunzip streams" in {
       ourEncode(largeTextBytes).length should be < streamEncode(largeTextBytes).length
     }
     "throw an error on truncated input" in {
-      pending // FIXME: unbreak
       val ex = the[RuntimeException] thrownBy ourDecode(streamEncode(smallTextBytes).dropRight(5))
       ex.getCause.getMessage should equal("Truncated GZIP stream")
     }
diff --git a/akka-http/src/main/scala/akka/http/scaladsl/coding/Decoder.scala b/akka-http/src/main/scala/akka/http/scaladsl/coding/Decoder.scala
index 951328895b..e4227db256 100644
--- a/akka-http/src/main/scala/akka/http/scaladsl/coding/Decoder.scala
+++ b/akka-http/src/main/scala/akka/http/scaladsl/coding/Decoder.scala
@@ -28,7 +28,7 @@ trait Decoder {
 
   def decoderFlow: Flow[ByteString, ByteString, Unit]
   def decode(input: ByteString)(implicit mat: Materializer): Future[ByteString] =
-    Source.single(input).via(decoderFlow).runWith(Sink.head)
+    Source.single(input).via(decoderFlow).runWith(Sink.fold(ByteString.empty)(_ ++ _))
 }
 object Decoder {
   val MaxBytesPerChunkDefault: Int = 65536