diff --git a/src/Shimakaze.Sdk.Hva/HvaReader.cs b/src/Shimakaze.Sdk.Hva/HvaReader.cs
index 92922546..024217ca 100644
--- a/src/Shimakaze.Sdk.Hva/HvaReader.cs
+++ b/src/Shimakaze.Sdk.Hva/HvaReader.cs
@@ -25,6 +25,7 @@ public override async Task<HvaFile> ReadAsync(IProgress<float>? progress = defau
         for (int i = 0; i < hva.Frames.Length; i++)
         {
             cancellationToken.ThrowIfCancellationRequested();
+            hva.Frames[i] ??= new();
             progress?.Report(1f / 3 + 2f / 3 * ((float)i / hva.Frames.Length));
 
             hva.Frames[i].Matrices = new HvaMatrix[hva.Header.NumSections];