diff --git a/src/MIDTesters.Core/Job/TestMid0038.cs b/src/MIDTesters.Core/Job/TestMid0038.cs
index 901cdc2..bc412f1 100644
--- a/src/MIDTesters.Core/Job/TestMid0038.cs
+++ b/src/MIDTesters.Core/Job/TestMid0038.cs
@@ -14,7 +14,7 @@ public void Mid0038Revision1()
             string package = "00220038001         01";
             var mid = _midInterpreter.Parse<Mid0038>(package);
 
-            Assert.IsNotNull(mid.JobId);
+            Assert.AreEqual(1, mid.JobId);
             AssertEqualPackages(package, mid);
         }
 
@@ -26,7 +26,7 @@ public void Mid0038ByteRevision1()
             byte[] bytes = GetAsciiBytes(package);
             var mid = _midInterpreter.Parse<Mid0038>(bytes);
 
-            Assert.IsNotNull(mid.JobId);
+            Assert.AreEqual(1, mid.JobId);
             AssertEqualPackages(bytes, mid);
         }
 
@@ -37,7 +37,7 @@ public void Mid0038Revision2()
             string package = "00240038002         0001";
             var mid = _midInterpreter.Parse<Mid0038>(package);
 
-            Assert.IsNotNull(mid.JobId);
+            Assert.AreEqual(1, mid.JobId);
             AssertEqualPackages(package, mid);
         }
 
@@ -49,8 +49,20 @@ public void Mid0038ByteRevision2()
             byte[] bytes = GetAsciiBytes(package);
             var mid = _midInterpreter.Parse<Mid0038>(bytes);
 
-            Assert.IsNotNull(mid.JobId);
+            Assert.AreEqual(1, mid.JobId);
             AssertEqualPackages(bytes, mid);
         }
+
+        [TestMethod]
+        [TestCategory("Revision 2"), TestCategory("ByteArray")]
+        public void Mid0038PackRevision2()
+        {
+            var mid = new Mid0038(2);
+            mid.JobId = 1;
+            var actual = mid.PackBytes();
+            var package = "00240038002         0001";
+
+            CollectionAssert.AreEqual(GetAsciiBytes(package), actual);
+        }
     }
 }
diff --git a/src/MIDTesters.Core/MidTester.cs b/src/MIDTesters.Core/MidTester.cs
index 4c34234..2737c9e 100644
--- a/src/MIDTesters.Core/MidTester.cs
+++ b/src/MIDTesters.Core/MidTester.cs
@@ -35,7 +35,7 @@ protected void AssertEqualPackages(string expected, Mid mid, bool useEmptyRevisi
             Assert.AreEqual(expected, mid.Pack());
         }
 
-        protected void AssertEqualPackages(IEnumerable<byte> expected, Mid mid, bool useEmptyRevision = false)
+        protected void AssertEqualPackages(IReadOnlyCollection<byte> expected, Mid mid, bool useEmptyRevision = false)
         {
             if (useEmptyRevision)
             {
@@ -43,7 +43,7 @@ protected void AssertEqualPackages(IEnumerable<byte> expected, Mid mid, bool use
             }
 
             mid.Header.StationId = mid.Header.SpindleId = null;
-            Assert.IsTrue(mid.PackBytes().SequenceEqual(expected));
+            CollectionAssert.AreEqual(expected.ToArray(), mid.PackBytes());
         }
     }
 }
diff --git a/src/OpenProtocolInterpreter/Job/Mid0038.cs b/src/OpenProtocolInterpreter/Job/Mid0038.cs
index 7666569..1963ffb 100644
--- a/src/OpenProtocolInterpreter/Job/Mid0038.cs
+++ b/src/OpenProtocolInterpreter/Job/Mid0038.cs
@@ -58,23 +58,26 @@ protected override Dictionary<int, List<DataField>> RegisterDatafields()
             {
                 {
                     1, new List<DataField>()
-                            {
-                                DataField.Number(DataFields.JobId, 20, 2, false),
-                            }
+                    {
+                        DataField.Number(DataFields.JobId, 20, GetJobIdSize(), false),
+                    }
                 }
             };
         }
 
         private void HandleRevision()
         {
-            if (Header.Revision > 1)
-            {
-                GetField(1, DataFields.JobId).Size = 4;
-            }
-            else
+            var dataField = GetField(1, DataFields.JobId);
+            dataField.Size = GetJobIdSize();
+        }
+
+        private int GetJobIdSize()
+        {
+            return Header.StandardizedRevision switch
             {
-                GetField(1, DataFields.JobId).Size = 2;
-            }
+                <= 1 => 2,
+                _ => 4
+            };
         }
 
         protected enum DataFields
diff --git a/src/OpenProtocolInterpreter/MID.cs b/src/OpenProtocolInterpreter/MID.cs
index 8bc55ee..69fe328 100644
--- a/src/OpenProtocolInterpreter/MID.cs
+++ b/src/OpenProtocolInterpreter/MID.cs
@@ -38,8 +38,8 @@ protected virtual string BuildHeader()
         {
             if (RevisionsByFields.Any())
             {
-                Header.Length = 20;
-                for (int i = 1; i <= (Header.Revision > 0 ? Header.Revision : 1); i++)
+                Header.Length = Header.DefaultSize;
+                for (int i = 1; i <= Header.StandardizedRevision; i++)
                 {
                     if (RevisionsByFields.TryGetValue(i, out var dataFields))
                     {
@@ -59,7 +59,7 @@ public virtual string Pack()
 
             var builder = new StringBuilder(header);
             int prefixIndex = 1;
-            var revision = (Header.Revision > 0 ? Header.Revision : 1);
+            var revision = Header.StandardizedRevision;
             for (int i = 1; i <= revision; i++)
             {
                 builder.Append(Pack(i, ref prefixIndex));