diff --git a/Capy64/Runtime/Libraries/FileSystem.cs b/Capy64/Runtime/Libraries/FileSystem.cs
index c946444..97c22a8 100644
--- a/Capy64/Runtime/Libraries/FileSystem.cs
+++ b/Capy64/Runtime/Libraries/FileSystem.cs
@@ -509,7 +509,7 @@ public class FileSystem : IComponent
         var mode = L.OptString(2, "r");
 
         var errorMessage = "invalid file mode";
-        if (mode.Length < 1 && mode.Length > 2)
+        if (mode.Length < 1)
         {
             L.ArgumentError(2, errorMessage);
             return 0;
@@ -541,20 +541,6 @@ public class FileSystem : IComponent
                 return 0;
         }
 
-        bool binaryMode = false;
-        if (mode.Length == 2)
-        {
-            if (mode[1] == 'b')
-            {
-                binaryMode = true;
-            }
-            else
-            {
-                L.ArgumentError(2, errorMessage);
-                return 0;
-            }
-        }
-
         try
         {
             var fileStream = File.Open(path, fileMode, fileAccess, FileShare.ReadWrite | FileShare.Delete);