diff --git a/themes/patek/assets/js/dark-mode.js b/themes/patek/assets/js/dark-mode.js
index ddaff24..8d24f97 100644
--- a/themes/patek/assets/js/dark-mode.js
+++ b/themes/patek/assets/js/dark-mode.js
@@ -1,5 +1,21 @@
 document.addEventListener("DOMContentLoaded", () => {
-	if (window.location.search.indexOf("darkmode=true") > -1) {
-		document.getElementById("content").classList.add("dark-mode");
+	if (window.location.search.indexOf("darkmode=false") > -1) {
+		document.cookie = "darkmode=false; path=/";
+		try {
+			document.getElementById("content").classList.remove("dark-mode");
+		} catch (error) {
+			if (error.message !== "document.getElementById(...) is null") {
+				throw error;
+			}
+		}
+	} else if (window.location.search.indexOf("darkmode=true") > -1 || document.cookie.indexOf("darkmode=true") > -1) {
+		document.cookie = "darkmode=true; path=/";
+		try {
+			document.getElementById("content").classList.add("dark-mode");
+		} catch (error) {
+			if (error.message !== "document.getElementById(...) is null") {
+				throw error;
+			}
+		}
 	}
 });