diff --git a/apps/server/src/services/tree.ts b/apps/server/src/services/tree.ts
index 54013e895..6211c5cd0 100644
--- a/apps/server/src/services/tree.ts
+++ b/apps/server/src/services/tree.ts
@@ -92,7 +92,10 @@ function sortNotes(parentNoteId: string, customSortBy: string = "title", reverse
         }
 
         const notes = note.getChildNotes();
-        const normalize = (obj: any) => (obj && typeof obj === "string" ? obj.toLowerCase() : obj);
+
+        function normalize<T>(obj: T | string) {
+            return obj && typeof obj === "string" ? obj.toLowerCase() : obj;
+        }
 
         notes.sort((a, b) => {
             if (foldersFirst) {
@@ -106,7 +109,7 @@ function sortNotes(parentNoteId: string, customSortBy: string = "title", reverse
             }
 
             function fetchValue(note: BNote, key: string) {
-                let rawValue;
+                let rawValue: string | null;
 
                 if (key === "title") {
                     const branch = note.getParentBranches().find((branch) => branch.parentNoteId === parentNoteId);
@@ -151,15 +154,15 @@ function sortNotes(parentNoteId: string, customSortBy: string = "title", reverse
                 return compare(bottomBEl, bottomAEl) * (reverse ? -1 : 1);
             }
 
-            const customAEl = fetchValue(a, customSortBy) ?? fetchValue(a, "title");
-            const customBEl = fetchValue(b, customSortBy) ?? fetchValue(b, "title");
+            const customAEl = fetchValue(a, customSortBy) ?? fetchValue(a, "title") as string;
+            const customBEl = fetchValue(b, customSortBy) ?? fetchValue(b, "title")  as string;
 
             if (customAEl !== customBEl) {
                 return compare(customAEl, customBEl);
             }
 
-            const titleAEl = fetchValue(a, "title");
-            const titleBEl = fetchValue(b, "title");
+            const titleAEl = fetchValue(a, "title") as string;
+            const titleBEl = fetchValue(b, "title") as string;
 
             return compare(titleAEl, titleBEl);
         });