diff --git a/CD/FullTOC.cs b/CD/FullTOC.cs
index d1432bb..0e19713 100644
--- a/CD/FullTOC.cs
+++ b/CD/FullTOC.cs
@@ -638,12 +638,9 @@ public static class FullTOC
             toc.LastCompleteSession = (byte)track.Session;
         }
 
-        if(!sessionEndingTrack.ContainsKey(toc.LastCompleteSession))
-        {
-            sessionEndingTrack[toc.LastCompleteSession] = (byte)tracks.
-                                                                Where(t => t.Session == toc.LastCompleteSession).
-                                                                Max(t => t.Sequence);
-        }
+        sessionEndingTrack.TryAdd(toc.LastCompleteSession, (byte)tracks.
+                                                                 Where(t => t.Session == toc.LastCompleteSession).
+                                                                 Max(t => t.Sequence));
 
         byte currentSession = 0;
 
diff --git a/SCSI/Sense.cs b/SCSI/Sense.cs
index 8426774..44f5c9f 100644
--- a/SCSI/Sense.cs
+++ b/SCSI/Sense.cs
@@ -340,8 +340,7 @@ public static class Sense
 
                 Array.Copy(sense, offset, desc, 0, descLen);
 
-                if(!decoded.Descriptors.ContainsKey(descType))
-                    decoded.Descriptors.Add(descType, desc);
+                decoded.Descriptors.TryAdd(descType, desc);
 
                 offset += descLen;
             }