diff --git a/SignalServiceKit/Messages/Attachments/V2/Thumbnails/AttachmentThumbnailServiceImpl.swift b/SignalServiceKit/Messages/Attachments/V2/Thumbnails/AttachmentThumbnailServiceImpl.swift
index bfd037d389..ad42335e74 100644
--- a/SignalServiceKit/Messages/Attachments/V2/Thumbnails/AttachmentThumbnailServiceImpl.swift
+++ b/SignalServiceKit/Messages/Attachments/V2/Thumbnails/AttachmentThumbnailServiceImpl.swift
@@ -58,7 +58,7 @@ public class AttachmentThumbnailServiceImpl: AttachmentThumbnailService {
                         relativeFilePath: attachmentStream.localRelativeFilePath
                     ),
                     encryptionKey: attachmentStream.attachment.encryptionKey,
-                    plaintextLength: attachmentStream.encryptedByteCount,
+                    plaintextLength: attachmentStream.unencryptedByteCount,
                     mimeType: attachmentStream.mimeType
                 )
                 .resized(maxDimensionPoints: quality.thumbnailDimensionPoints())