diff --git a/server/models/Author.js b/server/models/Author.js
index f3bbba57..40e7f75a 100644
--- a/server/models/Author.js
+++ b/server/models/Author.js
@@ -1,5 +1,6 @@
 const { DataTypes, Model, where, fn, col } = require('sequelize')
 const parseNameString = require('../utils/parsers/parseNameString')
+const { asciiOnlyToLowerCase } = require('../utils/index')
 
 class Author extends Model {
   constructor(values, options) {
@@ -55,7 +56,7 @@ class Author extends Model {
   static async getByNameAndLibrary(authorName, libraryId) {
     return this.findOne({
       where: [
-        where(fn('lower', col('name')), authorName.toLowerCase()),
+        where(fn('lower', col('name')), asciiOnlyToLowerCase(authorName)),
         {
           libraryId
         }
diff --git a/server/models/Series.js b/server/models/Series.js
index c57a1a11..dc8d110f 100644
--- a/server/models/Series.js
+++ b/server/models/Series.js
@@ -1,6 +1,7 @@
 const { DataTypes, Model, where, fn, col } = require('sequelize')
 
 const { getTitlePrefixAtEnd } = require('../utils/index')
+const { asciiOnlyToLowerCase } = require('../utils/index')
 
 class Series extends Model {
   constructor(values, options) {
@@ -41,7 +42,7 @@ class Series extends Model {
   static async getByNameAndLibrary(seriesName, libraryId) {
     return this.findOne({
       where: [
-        where(fn('lower', col('name')), seriesName.toLowerCase()),
+        where(fn('lower', col('name')), asciiOnlyToLowerCase(seriesName)),
         {
           libraryId
         }