diff --git a/src/services/utils.ts b/src/services/utils.ts
index 6b2974df0..aef261a6a 100644
--- a/src/services/utils.ts
+++ b/src/services/utils.ts
@@ -156,9 +156,9 @@ const STRING_MIME_TYPES = [
     "image/svg+xml"
 ];
 
-function isStringNote(type: string, mime: string) {
+function isStringNote(type: string | null, mime: string) {
     // render and book are string note in the sense that they are expected to contain empty string
-    return ["text", "code", "relationMap", "search", "render", "book", "mermaid", "canvas"].includes(type)
+    return (type && ["text", "code", "relationMap", "search", "render", "book", "mermaid", "canvas"].includes(type))
         || mime.startsWith('text/')
         || STRING_MIME_TYPES.includes(mime);
 }
diff --git a/src/share/shaca/entities/sattachment.js b/src/share/shaca/entities/sattachment.ts
similarity index 61%
rename from src/share/shaca/entities/sattachment.js
rename to src/share/shaca/entities/sattachment.ts
index 998c5ac95..352d34749 100644
--- a/src/share/shaca/entities/sattachment.js
+++ b/src/share/shaca/entities/sattachment.ts
@@ -1,39 +1,44 @@
 "use strict";
 
-const sql = require('../../sql');
-const utils = require('../../../services/utils');
-const AbstractShacaEntity = require('./abstract_shaca_entity');
+import sql = require('../../sql');
+import utils = require('../../../services/utils');
+import AbstractShacaEntity = require('./abstract_shaca_entity');
+import SNote = require('./snote');
+import { Blob } from '../../../services/blob-interface';
+
+type AttachmentRow = [ string, string, string, string, string, string, string ];
 
 class SAttachment extends AbstractShacaEntity {
-    constructor([attachmentId, ownerId, role, mime, title, blobId, utcDateModified]) {
+    private attachmentId: string;
+    private ownerId: string;
+    title: string;
+    private role: string;
+    private mime: string;
+    private blobId: string;
+    /** used for caching of images */
+    private utcDateModified: string;
+
+    constructor([attachmentId, ownerId, role, mime, title, blobId, utcDateModified]: AttachmentRow) {
         super();
 
-        /** @param {string} */
         this.attachmentId = attachmentId;
-        /** @param {string} */
         this.ownerId = ownerId;
-        /** @param {string} */
         this.title = title;
-        /** @param {string} */
         this.role = role;
-        /** @param {string} */
         this.mime = mime;
-        /** @param {string} */
         this.blobId = blobId;
-        /** @param {string} */
-        this.utcDateModified = utcDateModified; // used for caching of images
+        this.utcDateModified = utcDateModified;
 
         this.shaca.attachments[this.attachmentId] = this;
         this.shaca.notes[this.ownerId].attachments.push(this);
     }
 
-    /** @returns {SNote} */
-    get note() {
+    get note(): SNote {
         return this.shaca.notes[this.ownerId];
     }
 
     getContent(silentNotFoundError = false) {
-        const row = sql.getRow(`SELECT content FROM blobs WHERE blobId = ?`, [this.blobId]);
+        const row = sql.getRow<Pick<Blob, "content">>(`SELECT content FROM blobs WHERE blobId = ?`, [this.blobId]);
 
         if (!row) {
             if (silentNotFoundError) {
@@ -56,7 +61,7 @@ class SAttachment extends AbstractShacaEntity {
         }
     }
 
-    /** @returns {boolean} true if the attachment has string content (not binary) */
+    /** @returns true if the attachment has string content (not binary) */
     hasStringContent() {
         return utils.isStringNote(null, this.mime);
     }
@@ -67,11 +72,10 @@ class SAttachment extends AbstractShacaEntity {
             role: this.role,
             mime: this.mime,
             title: this.title,
-            position: this.position,
             blobId: this.blobId,
             utcDateModified: this.utcDateModified
         };
     }
 }
 
-module.exports = SAttachment;
+export = SAttachment;
diff --git a/src/share/shaca/entities/snote.ts b/src/share/shaca/entities/snote.ts
index 5883fdf88..1574271be 100644
--- a/src/share/shaca/entities/snote.ts
+++ b/src/share/shaca/entities/snote.ts
@@ -6,6 +6,7 @@ import AbstractShacaEntity = require('./abstract_shaca_entity');
 import escape = require('escape-html');
 import { AttributeRow } from '../../../becca/entities/rows';
 import { Blob } from '../../../services/blob-interface';
+import SAttachment = require('./sattachment');
 
 const LABEL = 'label';
 const RELATION = 'relation';
@@ -30,7 +31,7 @@ class SNote extends AbstractShacaEntity {
     private __attributeCache: any[] | null; // fixme
     private __inheritableAttributeCache: any[] | null; // fixme
     private targetRelations: any[]; // fixme: SAttribute[]
-    private attachments: any[] ;        // fixme: SAttachment[]
+    private attachments: SAttachment[];
 
     constructor([noteId, title, type, mime, blobId, utcDateModified, isProtected]: NoteRow) {
         super();
@@ -120,15 +121,9 @@ class SNote extends AbstractShacaEntity {
         let content = row.content;
 
         if (this.hasStringContent()) {
-            if (content == null) {
-                return "";
-            }
-
-            if (typeof content !== "string") {
-                return content.toString("utf-8");
-            }
-
-            return content;
+            return content === null
+                ? ""
+                : content.toString("utf-8");
         }
         else {
             return content;
@@ -470,17 +465,14 @@ class SNote extends AbstractShacaEntity {
         return this.targetRelations;
     }
 
-    /** @returns {SAttachment[]} */
     getAttachments() {
         return this.attachments;
     }
 
-    /** @returns {SAttachment} */
     getAttachmentByTitle(title: string) {
         return this.attachments.find(attachment => attachment.title === title);
     }
 
-    /** @returns {string} */
     get shareId() {
         if (this.hasOwnedLabel('shareRoot')) {
             return "";
@@ -519,4 +511,4 @@ class SNote extends AbstractShacaEntity {
     }
 }
 
-module.exports = SNote;
+export = SNote;
diff --git a/src/share/shaca/shaca_loader.js b/src/share/shaca/shaca_loader.js
index 77348e697..418311a79 100644
--- a/src/share/shaca/shaca_loader.js
+++ b/src/share/shaca/shaca_loader.js
@@ -6,7 +6,7 @@ const log = require('../../services/log');
 const SNote = require('./entities/snote');
 const SBranch = require('./entities/sbranch.js');
 const SAttribute = require('./entities/sattribute.js');
-const SAttachment = require('./entities/sattachment.js');
+const SAttachment = require('./entities/sattachment');
 const shareRoot = require('../share_root');
 const eventService = require('../../services/events');