diff --git a/Shared/ArticleStyles/ArticleThemeDownloader.swift b/Shared/ArticleStyles/ArticleThemeDownloader.swift
index dbc6d9ca9..978fe0cae 100644
--- a/Shared/ArticleStyles/ArticleThemeDownloader.swift
+++ b/Shared/ArticleStyles/ArticleThemeDownloader.swift
@@ -77,7 +77,7 @@ public class ArticleThemeDownloader: Logging {
 	private func findThemeFile(in searchPath: String) -> String? {
 		if let directoryContents = FileManager.default.enumerator(atPath: searchPath) {
 			while let file = directoryContents.nextObject() as? String {
-				if file.localizedCaseInsensitiveContains("__MACOSX") {
+				if file.hasPrefix("__MACOSX/") {
 					logger.debug("Ignoring theme file in __MACOSX folder.")
 					continue
 				}