diff --git a/WindivertDotnet.Test/TcpHeaderTest.cs b/WindivertDotnet.Test/TcpHeaderTest.cs
index 2271099..c4c8a06 100644
--- a/WindivertDotnet.Test/TcpHeaderTest.cs
+++ b/WindivertDotnet.Test/TcpHeaderTest.cs
@@ -35,7 +35,6 @@ public void WriteTest()
                 Ack = true,
                 Fin = true,
                 Psh = true,
-                Syn = true,
                 Urg = true,
                 Rst = true,
 
@@ -57,7 +56,7 @@ public void WriteTest()
             Assert.True(header.Flags.HasFlag(TcpFlag.Psh));
             Assert.True(header.Flags.HasFlag(TcpFlag.Rst));
             Assert.True(header.Flags.HasFlag(TcpFlag.Fin));
-            Assert.True(header.Flags.HasFlag(TcpFlag.Syn));
+            Assert.False(header.Flags.HasFlag(TcpFlag.Syn));
 
             Assert.Equal(2U, header.AckNum);
             Assert.Equal(3, header.Checksum);
@@ -68,6 +67,12 @@ public void WriteTest()
             Assert.Equal(12U, header.SeqNum);
             Assert.Equal(13, header.SrcPort);
             Assert.Equal(16, header.Window);
+
+
+            header.Flags &= ~(TcpFlag.Fin | TcpFlag.Rst);
+            Assert.False(header.Flags.HasFlag(TcpFlag.Rst));
+            Assert.False(header.Flags.HasFlag(TcpFlag.Fin));
+
         }
     }
 }
diff --git a/WindivertDotnet/TcpHeader.cs b/WindivertDotnet/TcpHeader.cs
index f996ab7..1ec80df 100644
--- a/WindivertDotnet/TcpHeader.cs
+++ b/WindivertDotnet/TcpHeader.cs
@@ -94,7 +94,7 @@ public byte HdrLength
         public bool Fin
         {
             get => this.Flags.HasFlag(TcpFlag.Fin);
-            set => this.Flags |= TcpFlag.Fin;
+            set => this.SetFlag(TcpFlag.Fin, value);
         }
 
         /// <summary>
@@ -103,7 +103,7 @@ public bool Fin
         public bool Syn
         {
             get => this.Flags.HasFlag(TcpFlag.Syn);
-            set => this.Flags |= TcpFlag.Syn;
+            set => this.SetFlag(TcpFlag.Syn, value);
         }
 
         /// <summary>
@@ -112,7 +112,7 @@ public bool Syn
         public bool Rst
         {
             get => this.Flags.HasFlag(TcpFlag.Rst);
-            set => this.Flags |= TcpFlag.Rst;
+            set => this.SetFlag(TcpFlag.Rst, value);
         }
 
         /// <summary>
@@ -121,7 +121,7 @@ public bool Rst
         public bool Psh
         {
             get => this.Flags.HasFlag(TcpFlag.Psh);
-            set => this.Flags |= TcpFlag.Psh;
+            set => this.SetFlag(TcpFlag.Psh, value);
         }
 
         /// <summary>
@@ -130,7 +130,7 @@ public bool Psh
         public bool Ack
         {
             get => this.Flags.HasFlag(TcpFlag.Ack);
-            set => this.Flags |= TcpFlag.Ack;
+            set => this.SetFlag(TcpFlag.Ack, value);
         }
 
         /// <summary>
@@ -139,7 +139,7 @@ public bool Ack
         public bool Urg
         {
             get => this.Flags.HasFlag(TcpFlag.Urg);
-            set => this.Flags |= TcpFlag.Urg;
+            set => this.SetFlag(TcpFlag.Urg, value);
         }
 
         [DebuggerBrowsable(DebuggerBrowsableState.Never)]
@@ -177,5 +177,17 @@ public ushort UrgPtr
             get => BinaryPrimitives.ReverseEndianness(urgPtr);
             set => urgPtr = BinaryPrimitives.ReverseEndianness(value);
         }
+
+        private void SetFlag(TcpFlag flag, bool value)
+        {
+            if (value)
+            {
+                this.Flags |= flag;
+            }
+            else
+            {
+                this.Flags &= ~flag;
+            }
+        }
     }
 }