diff --git a/RDMSharp/Metadata/JSON/OneOfTypes/BitFieldType.cs b/RDMSharp/Metadata/JSON/OneOfTypes/BitFieldType.cs
index b295b2d..b4cc648 100644
--- a/RDMSharp/Metadata/JSON/OneOfTypes/BitFieldType.cs
+++ b/RDMSharp/Metadata/JSON/OneOfTypes/BitFieldType.cs
@@ -70,7 +70,7 @@ public BitFieldType(string name,
             ValueForUnspecified = valueForUnspecified;
             Bits = bits;
         }
-        public BitFieldType(string name, ushort size, BitType[] bits) : this(name, null, null, null, "bitField", size, null, bits)
+        public BitFieldType(string name, ushort size, BitType[] bits, bool valueForUnspecified = false) : this(name, null, null, null, "bitField", size, valueForUnspecified, bits)
         {
         }
 
@@ -91,9 +91,9 @@ public override byte[] ParsePayloadToData(DataTree dataTree)
                 throw new ArithmeticException($"The given {nameof(dataTree.Children)}.{nameof(dataTree.Children.Length)}({dataTree.Children.Length}) not match {nameof(Bits)}.{nameof(Bits.Length)}({Bits.Length})");
 
             bool[] data = new bool[Size];
-            if (ValueForUnspecified.HasValue)
+            if (ValueForUnspecified == true)
                 for (int i = 0; i < Size; i++)
-                    data[i] = ValueForUnspecified.Value;
+                    data[i] = true;
 
             foreach (DataTree bitDataTree in dataTree.Children)
             {
@@ -128,6 +128,16 @@ public override DataTree ParseDataToPayload(ref byte[] data)
                 BitType bitType = Bits[i];
                 bitDataTrees.Add(new DataTree(bitType.Name, i, bools[bitType.Index]));
             }
+            bool valueForUnspecified = ValueForUnspecified == true;
+            for(int i = 0; i < bools.Length; i++)
+            {
+                if (Bits.Any(b => b.Index == i))
+                    continue;
+
+                bool bit= bools[i];
+                if (bit != valueForUnspecified)
+                    issueList.Add(new DataTreeIssue($"The Bit at Index {i} is Unspecified, but the Value is not {valueForUnspecified} as defined for Unspecified Bits"));
+            }
             return new DataTree(this.Name, 0, children: bitDataTrees.OrderBy(b=>b.Index).ToArray(), issueList.Count != 0 ? issueList.ToArray() : null);
         }
     }
diff --git a/RDMSharpTests/Metadata/JSON/TestBitFieldType.cs b/RDMSharpTests/Metadata/JSON/TestBitFieldType.cs
index 5fd30cd..076eceb 100644
--- a/RDMSharpTests/Metadata/JSON/TestBitFieldType.cs
+++ b/RDMSharpTests/Metadata/JSON/TestBitFieldType.cs
@@ -34,6 +34,11 @@ public void TestMany()
             var dataTree= new DataTree(bitFieldType.Name,0,new DataTree[] { new DataTree(bitTypes[0].Name, 0, true), new DataTree(bitTypes[1].Name, 1, true), new DataTree(bitTypes[2].Name, 2, true), });
 
             DoParseDataTest(bitFieldType, dataTree, new byte[] { 0b00010100, 0b10000000 });
+
+            bitFieldType = new BitFieldType("NAME_BIT_FIELD", 16, bitTypes, true);
+            dataTree = new DataTree(bitFieldType.Name, 0, new DataTree[] { new DataTree(bitTypes[0].Name, 0, false), new DataTree(bitTypes[1].Name, 1, false), new DataTree(bitTypes[2].Name, 2, false), });
+            Assert.That(bitFieldType.ValueForUnspecified, Is.True);
+            DoParseDataTest(bitFieldType, dataTree, new byte[] { 0b11101011, 0b01111111 });
         }
         private void DoParseDataTest(BitFieldType bitFieldType, DataTree dataTree, byte[] expectedData, string message = null)
         {