diff --git a/src/becca/entities/bnote.js b/src/becca/entities/bnote.js
index 4225908a9..b009cef29 100644
--- a/src/becca/entities/bnote.js
+++ b/src/becca/entities/bnote.js
@@ -1496,7 +1496,7 @@ class BNote extends AbstractBeccaEntity {
         parentNote.setContent(fixedContent);
 
         const noteService = require("../../services/notes");
-        noteService.asyncPostProcessContent(parentNote, fixedContent);
+        noteService.asyncPostProcessContent(parentNote, fixedContent); // to mark an unused attachment for deletion
 
         this.deleteNote();
 
diff --git a/src/services/image.js b/src/services/image.js
index a6b08a4d5..de71493f3 100644
--- a/src/services/image.js
+++ b/src/services/image.js
@@ -142,15 +142,21 @@ function saveImageToAttachment(noteId, uploadBuffer, originalName, shrinkImageSw
     const fileName = sanitizeFilename(originalName);
     const note = becca.getNoteOrThrow(noteId);
 
-    const attachment = note.saveAttachment({
+    let attachment = note.saveAttachment({
         role: 'image',
         mime: 'unknown',
         title: fileName
     });
 
+    const noteService = require("../services/notes");
+    noteService.asyncPostProcessContent(note, note.getContent()); // to mark an unused attachment for deletion
+
     // resizing images asynchronously since JIMP does not support sync operation
     processImage(uploadBuffer, originalName, shrinkImageSwitch).then(({buffer, imageFormat}) => {
         sql.transactional(() => {
+            // re-read, might be changed in the meantime
+            attachment = becca.getAttachmentOrThrow(attachment.attachmentId);
+
             attachment.mime = getImageMimeFromExtension(imageFormat.ext);
 
             if (!originalName.includes(".")) {