diff --git a/DiscImageChef.Filesystems/ISO9660/File.cs b/DiscImageChef.Filesystems/ISO9660/File.cs
index 6b8430f8f..0e29ca7bf 100644
--- a/DiscImageChef.Filesystems/ISO9660/File.cs
+++ b/DiscImageChef.Filesystems/ISO9660/File.cs
@@ -51,16 +51,16 @@ namespace DiscImageChef.Filesystems.ISO9660
 
             if(entry.Flags.HasFlag(FileFlags.Directory) && !debug) return Errno.IsDirectory;
 
-            if(offset >= entry.Size) return Errno.InvalidArgument;
-
-            if(size + offset >= entry.Size) size = entry.Size - offset;
-
             if(entry.Size == 0)
             {
                 buf = new byte[0];
                 return Errno.NoError;
             }
 
+            if(offset >= entry.Size) return Errno.InvalidArgument;
+
+            if(size + offset >= entry.Size) size = entry.Size - offset;
+
             // TODO: XA
             long firstSector    = offset                  / 2048;
             long offsetInSector = offset                  % 2048;