diff --git a/src/SharpCompress/Common/SevenZip/CMethodId.cs b/src/SharpCompress/Common/SevenZip/CMethodId.cs
index ee9e3bb3..03ce8df6 100644
--- a/src/SharpCompress/Common/SevenZip/CMethodId.cs
+++ b/src/SharpCompress/Common/SevenZip/CMethodId.cs
@@ -1,6 +1,6 @@
 namespace SharpCompress.Common.SevenZip
 {
-    internal struct CMethodId
+    internal readonly struct CMethodId
     {
         public const ulong K_COPY_ID = 0;
         public const ulong K_LZMA_ID = 0x030101;
@@ -26,7 +26,7 @@
 
         public override bool Equals(object obj)
         {
-            return obj is CMethodId && (CMethodId)obj == this;
+            return obj is CMethodId other && Equals(other);
         }
 
         public bool Equals(CMethodId other)