diff --git a/src/routes/api/branches.js b/src/routes/api/branches.js
index c313f5aa3..4638fb63e 100644
--- a/src/routes/api/branches.js
+++ b/src/routes/api/branches.js
@@ -7,7 +7,7 @@ const treeService = require('../../services/tree');
 const eraseService = require('../../services/erase');
 const becca = require('../../becca/becca');
 const TaskContext = require('../../services/task_context');
-const branchService = require('../../services/branches.js');
+const branchService = require('../../services/branches');
 const log = require('../../services/log');
 const ValidationError = require('../../errors/validation_error');
 const eventService = require("../../services/events");
diff --git a/src/services/backend_script_api.js b/src/services/backend_script_api.js
index f7fcac10a..ff3e16be5 100644
--- a/src/services/backend_script_api.js
+++ b/src/services/backend_script_api.js
@@ -17,7 +17,7 @@ const becca = require('../becca/becca');
 const ws = require('./ws');
 const SpacedUpdate = require('./spaced_update.js');
 const specialNotesService = require('./special_notes.js');
-const branchService = require('./branches.js');
+const branchService = require('./branches');
 const exportService = require('./export/zip.js');
 const syncMutex = require('./sync_mutex');
 const backupService = require('./backup');
diff --git a/src/services/branches.js b/src/services/branches.ts
similarity index 61%
rename from src/services/branches.js
rename to src/services/branches.ts
index 7fab98cd1..7ee32c949 100644
--- a/src/services/branches.js
+++ b/src/services/branches.ts
@@ -1,7 +1,8 @@
-const treeService = require('./tree');
-const sql = require('./sql');
+import treeService = require('./tree');
+import sql = require('./sql');
+import BBranch = require('../becca/entities/bbranch.js');
 
-function moveBranchToNote(branchToMove, targetParentNoteId) {
+function moveBranchToNote(branchToMove: BBranch, targetParentNoteId: string) {
     if (branchToMove.parentNoteId === targetParentNoteId) {
         return {success: true}; // no-op
     }
@@ -12,8 +13,8 @@ function moveBranchToNote(branchToMove, targetParentNoteId) {
         return [200, validationResult];
     }
 
-    const maxNotePos = sql.getValue('SELECT MAX(notePosition) FROM branches WHERE parentNoteId = ? AND isDeleted = 0', [targetParentNoteId]);
-    const newNotePos = maxNotePos === null ? 0 : maxNotePos + 10;
+    const maxNotePos = sql.getValue<number | null>('SELECT MAX(notePosition) FROM branches WHERE parentNoteId = ? AND isDeleted = 0', [targetParentNoteId]);
+    const newNotePos = !maxNotePos ? 0 : maxNotePos + 10;
 
     const newBranch = branchToMove.createClone(targetParentNoteId, newNotePos);
     newBranch.save();
@@ -26,10 +27,10 @@ function moveBranchToNote(branchToMove, targetParentNoteId) {
     };
 }
 
-function moveBranchToBranch(branchToMove, targetParentBranch) {
+function moveBranchToBranch(branchToMove: BBranch, targetParentBranch: BBranch) {
     const res = moveBranchToNote(branchToMove, targetParentBranch.noteId);
 
-    if (!res.success) {
+    if (!("success" in res) || !res.success) {
         return res;
     }
 
@@ -42,7 +43,7 @@ function moveBranchToBranch(branchToMove, targetParentBranch) {
     return res;
 }
 
-module.exports = {
+export = {
     moveBranchToBranch,
     moveBranchToNote
 };
diff --git a/src/services/bulk_actions.js b/src/services/bulk_actions.js
index 136d1cccf..d894f2188 100644
--- a/src/services/bulk_actions.js
+++ b/src/services/bulk_actions.js
@@ -2,7 +2,7 @@ const log = require('./log');
 const revisionService = require('./revisions');
 const becca = require('../becca/becca');
 const cloningService = require('./cloning.js');
-const branchService = require('./branches.js');
+const branchService = require('./branches');
 const utils = require('./utils');
 const eraseService = require("./erase");
 
diff --git a/src/services/tree.ts b/src/services/tree.ts
index 56291b620..d731fe6b0 100644
--- a/src/services/tree.ts
+++ b/src/services/tree.ts
@@ -261,7 +261,7 @@ function setNoteToParent(noteId: string, prefix: string, parentNoteId: string) {
     }
 }
 
-module.exports = {
+export = {
     validateParentChild,
     sortNotes,
     sortNotesIfNeeded,