diff --git a/src/SharpCompress/Compressors/BZip2/CBZip2InputStream.cs b/src/SharpCompress/Compressors/BZip2/CBZip2InputStream.cs
index a467942f..cf006dbc 100644
--- a/src/SharpCompress/Compressors/BZip2/CBZip2InputStream.cs
+++ b/src/SharpCompress/Compressors/BZip2/CBZip2InputStream.cs
@@ -542,9 +542,14 @@ internal class CBZip2InputStream : Stream
             {
                 j++;
             }
-            selectorMtf[i] = (char)j;
+            if (i < BZip2Constants.MAX_SELECTORS)
+            {
+                selectorMtf[i] = (char)j;
+            }
         }
 
+        nSelectors = Math.Min(nSelectors, BZip2Constants.MAX_SELECTORS);
+
         /* Undo the MTF values for the selectors. */
         {
             var pos = new char[BZip2Constants.N_GROUPS];