diff --git a/Aaru.Images/CDRDAO/Write.cs b/Aaru.Images/CDRDAO/Write.cs
index 2f80a35e3..53f5ca754 100644
--- a/Aaru.Images/CDRDAO/Write.cs
+++ b/Aaru.Images/CDRDAO/Write.cs
@@ -593,7 +593,7 @@ namespace Aaru.DiscImages
                                                 flags.HasFlag(CdFlags.FourChannel) ? "FOUR" : "TWO");
                 }
 
-                if(_trackIsrcs.TryGetValue((byte)track.TrackSequence, out string isrc))
+                if(_trackIsrcs.TryGetValue((byte)track.TrackSequence, out string isrc)) && !string.IsNullOrWhiteSpace(isrc))
                     _descriptorStream.WriteLine("ISRC {0}", isrc);
 
                 (byte minute, byte second, byte frame) msf =
diff --git a/Aaru.Images/CDRWin/Write.cs b/Aaru.Images/CDRWin/Write.cs
index f8f127757..2c6cc6faa 100644
--- a/Aaru.Images/CDRWin/Write.cs
+++ b/Aaru.Images/CDRWin/Write.cs
@@ -513,7 +513,7 @@ namespace Aaru.DiscImages
                                                     flags.HasFlag(CdFlags.PreEmphasis) ? " PRE" : "");
                     }
 
-                if(_trackIsrcs.TryGetValue((byte)track.TrackSequence, out string isrc))
+                if(_trackIsrcs.TryGetValue((byte)track.TrackSequence, out string isrc)) && !string.IsNullOrWhiteSpace(isrc))
                     _descriptorStream.WriteLine("    ISRC {0}", isrc);
 
                 if(track.TrackPregap > 0)