diff --git a/src/services/attributes.ts b/src/services/attributes.ts
index 25b54724b..eff0f4697 100644
--- a/src/services/attributes.ts
+++ b/src/services/attributes.ts
@@ -9,7 +9,7 @@ import BUILTIN_ATTRIBUTES from "./builtin_attributes.js";
 import BNote from "../becca/entities/bnote.js";
 import { AttributeRow } from '../becca/entities/rows.js';
 
-const ATTRIBUTE_TYPES = ['label', 'relation'];
+const ATTRIBUTE_TYPES = new Set(['label', 'relation']);
 
 function getNotesWithLabel(name: string, value?: string): BNote[] {
     const query = attributeFormatter.formatAttrForSearch({type: 'label', name, value}, value !== undefined);
@@ -99,7 +99,7 @@ function getAttributeNames(type: string, nameLike: string) {
 }
 
 function isAttributeType(type: string): boolean {
-    return ATTRIBUTE_TYPES.includes(type);
+    return ATTRIBUTE_TYPES.has(type);
 }
 
 function isAttributeDangerous(type: string, name: string): boolean {
diff --git a/src/services/search/expressions/note_content_fulltext.ts b/src/services/search/expressions/note_content_fulltext.ts
index d81f42dcd..bc92cf26c 100644
--- a/src/services/search/expressions/note_content_fulltext.ts
+++ b/src/services/search/expressions/note_content_fulltext.ts
@@ -13,7 +13,7 @@ import { normalize } from "../../utils.js";
 import sql from "../../sql.js";
 
 
-const ALLOWED_OPERATORS = ['=', '!=', '*=*', '*=', '=*', '%='];
+const ALLOWED_OPERATORS = new Set(['=', '!=', '*=*', '*=', '=*', '%=']);
 
 const cachedRegexes: Record<string, RegExp> = {};
 
@@ -50,8 +50,8 @@ class NoteContentFulltextExp extends Expression {
     }
 
     execute(inputNoteSet: NoteSet, executionContext: {}, searchContext: SearchContext) {
-        if (!ALLOWED_OPERATORS.includes(this.operator)) {
-            searchContext.addError(`Note content can be searched only with operators: ${ALLOWED_OPERATORS.join(", ")}, operator ${this.operator} given.`);
+        if (!ALLOWED_OPERATORS.has(this.operator)) {
+            searchContext.addError(`Note content can be searched only with operators: ${Array.from(ALLOWED_OPERATORS).join(", ")}, operator ${this.operator} given.`);
 
             return inputNoteSet;
         }
diff --git a/src/services/search/services/parse.ts b/src/services/search/services/parse.ts
index d83f4fd39..5cd408d6b 100644
--- a/src/services/search/services/parse.ts
+++ b/src/services/search/services/parse.ts
@@ -44,7 +44,7 @@ function getFulltext(_tokens: TokenData[], searchContext: SearchContext) {
     }
 }
 
-const OPERATORS = [
+const OPERATORS = new Set([
     "=",
     "!=",
     "*=*",
@@ -55,14 +55,14 @@ const OPERATORS = [
     "<",
     "<=",
     "%="
-];
+]);
 
 function isOperator(token: TokenData) {
     if (Array.isArray(token)) {
         return false;
     }
 
-    return OPERATORS.includes(token.token);
+    return OPERATORS.has(token.token);
 }
 
 function getExpression(tokens: TokenData[], searchContext: SearchContext, level = 0) {
diff --git a/src/services/utils.ts b/src/services/utils.ts
index b4155bc33..040cefc02 100644
--- a/src/services/utils.ts
+++ b/src/services/utils.ts
@@ -152,19 +152,19 @@ export function getContentDisposition(filename: string) {
     return `file; filename="${sanitizedFilename}"; filename*=UTF-8''${sanitizedFilename}`;
 }
 
-const STRING_MIME_TYPES = [
+const STRING_MIME_TYPES = new Set([
     "application/javascript",
     "application/x-javascript",
     "application/json",
     "application/x-sql",
     "image/svg+xml"
-];
+]);
 
 export function isStringNote(type: string | undefined, mime: string) {
     // render and book are string note in the sense that they are expected to contain empty string
     return (type && ["text", "code", "relationMap", "search", "render", "book", "mermaid", "canvas"].includes(type))
         || mime.startsWith('text/')
-        || STRING_MIME_TYPES.includes(mime);
+        || STRING_MIME_TYPES.has(mime);
 }
 
 export function quoteRegex(url: string) {