diff --git a/RobSharper.Ros.BagReader.Tests/BagReaderTests.cs b/RobSharper.Ros.BagReader.Tests/BagReaderTests.cs
index 38969ed..20e5dc7 100644
--- a/RobSharper.Ros.BagReader.Tests/BagReaderTests.cs
+++ b/RobSharper.Ros.BagReader.Tests/BagReaderTests.cs
@@ -29,9 +29,12 @@ public void Can_create_bag_reader_for_v2_bag(string bagfile)
         public void Can_read_bag(string bagfile)
         {
             SetBagFile(bagfile);
-            
-            var rosbag = BagReaderFactory.Create(_bagStream, RecordVisitor.NullVisitor);
+
+            var visitorMock = new Mock<IBagRecordVisitor>();
+            var rosbag = BagReaderFactory.Create(_bagStream, visitorMock.Object);
             rosbag.ProcessAll();
+
+            visitorMock.Verify(x => x.Visit(It.IsAny<Chunk>()), Times.AtLeastOnce());
         }
 
 
diff --git a/RobSharper.Ros.BagReader/V2BagReader.cs b/RobSharper.Ros.BagReader/V2BagReader.cs
index f64b44f..bd14be0 100644
--- a/RobSharper.Ros.BagReader/V2BagReader.cs
+++ b/RobSharper.Ros.BagReader/V2BagReader.cs
@@ -69,7 +69,7 @@ public bool ProcessNext()
 
         private RosBinaryReader CreateRecordDataReader()
         {
-            var length = _reader.ReadInt32();
+            var length = _reader.ReadUInt32();
             var confinedStream = new ConfinedReadOnlyStream(_stream, length);
             var dataReader = new RosBinaryReader(confinedStream);