diff --git a/data/lightdm-webkit2-greeter.conf b/data/lightdm-webkit2-greeter.conf
index a1c1f0c..133f7ce 100644
--- a/data/lightdm-webkit2-greeter.conf
+++ b/data/lightdm-webkit2-greeter.conf
@@ -2,7 +2,7 @@
 # [greeter]
 # webkit-theme = Webkit theme to use. (Default: antergos)
 # debug_mode = Greeter theme debug mode. (Default: false)
-# screensaver-timeout = Blank the screen after this many seconds of inactivity.
+# screensaver-timeout = Blank the screen after this many seconds of inactivity. (Default: 300)
 #
 
 [greeter]
diff --git a/src/lightdm-webkit2-greeter-ext.c b/src/lightdm-webkit2-greeter-ext.c
index 3ad111c..c3aa6bc 100644
--- a/src/lightdm-webkit2-greeter-ext.c
+++ b/src/lightdm-webkit2-greeter-ext.c
@@ -60,7 +60,6 @@ GKeyFile *keyfile;
 /*
  * Put all our translatable strings up top
  */
-
 #define EXPECTSTRING   _("Expected a string")
 #define ARGNOTSUPPLIED _("Argument(s) not supplied")
 
diff --git a/src/lightdm-webkit2-greeter.c b/src/lightdm-webkit2-greeter.c
index c18c7d2..c69de0a 100644
--- a/src/lightdm-webkit2-greeter.c
+++ b/src/lightdm-webkit2-greeter.c
@@ -36,6 +36,7 @@
 #include <gtk/gtk.h>
 #include <gdk/gdkx.h>
 #include <glib.h>
+#include <glib/gprintf.h>
 #include <glib-unix.h>
 #include <gtk/gtkx.h>
 #include <webkit2/webkit2.h>
@@ -56,9 +57,10 @@ static GdkDisplay *default_display;
 
 /* Screensaver values */
 static int timeout, interval, prefer_blanking, allow_exposures;
+
 static gint config_timeout;
 
-static gboolean debug_mode;
+static gboolean debug_mode, heartbeat;
 
 static GdkFilterReturn
 wm_window_filter(GdkXEvent *gxevent, GdkEvent *event, gpointer data) {
@@ -105,6 +107,7 @@ create_new_webkit_settings_object(void) {
 		"javascript-can-open-windows-automatically", TRUE,
 		"allow-file-access-from-file-urls", TRUE,
 		"enable-write-console-messages-to-stdout", TRUE,
+		"allow-universal-access-from-file-urls", TRUE,
 		NULL
 	);
 }
@@ -125,6 +128,45 @@ context_menu_cb(WebKitWebView *view,
 }
 
 
+/**
+ * Callback for Theme Heartbeat. Themes start the heartbeat by sending a post message
+ * via JavaScript. Once started, the heartbeat will schedule a check to ensure that the
+ * theme has sent a subsequent heartbeat message. If heartbeat message was not received,
+ * we assume that there has been an error in the web process and fallback to the simple theme.
+ */
+static void
+theme_heartbeat_cb(void) {
+	if (! heartbeat) {
+		/* Setup g_timeout callback for theme heartbeat check */
+		g_timeout_add_seconds(G_PRIORITY_DEFAULT, 8, (GSourceFunc) check_theme_heartbeat_cb, NULL);
+		heartbeat = TRUE;
+	}
+}
+
+
+static gboolean
+check_theme_heartbeat_cb(void) {
+	if (! heartbeat) {
+			/* Theme heartbeat not received. We assume that an error has occured
+			 * which broke script execution. We will fallback to the simple theme
+			 * so the user won't be stuck with a broken login screen.
+			 */
+			g_print('%s%s',
+					'[ERROR] :: A problem was detected with the current theme. ',
+					'Falling back to simple theme...'
+			);
+			webkit_web_view_load_uri(
+					WEBKIT_WEB_VIEW(web_view),
+					g_strdup_printf("file://%s/simple/index.html", THEME_DIR)
+			);
+	}
+
+	heartbeat = FALSE;
+
+	return heartbeat;
+}
+
+
 /**
  * Lock Hint enabled handler.
  *
@@ -156,11 +198,23 @@ message_received_cb(WebKitUserContentManager *manager,
 					WebKitJavascriptResult *message,
 					gpointer user_data) {
 
-	/* TODO:
-	 * Abstract this by using JSON for exchanging messages so the handler can
-	 * be used for more than one task/event.
-	 */
-	lock_hint_enabled_handler();
+	gchar *message_str, *lock_hint_str, *heartbeat_str;
+
+	message_str = get_js_result_as_string(message);
+	lock_hint_str = "LockHint";
+	heartbeat_str = "Heartbeat";
+
+	switch(message_str) {
+		case lock_hint_str :
+			lock_hint_enabled_handler();
+			break;
+
+		case heartbeat_str :
+			theme_heartbeat_cb();
+			break;
+	}
+
+	g_free(message_str); g_free(lock_hint_str); g_free(heartbeat_str);
 
 }
 
diff --git a/themes/antergos/js/greeter.js b/themes/antergos/js/greeter.js
index b0003dc..006bcb7 100644
--- a/themes/antergos/js/greeter.js
+++ b/themes/antergos/js/greeter.js
@@ -60,12 +60,15 @@ class AntergosThemeUtils {
 		}
 		_util = this;
 
+		this.initialize_theme_heartbeat();
+
 		this.debug = false;
 		this.lang = window.navigator.language.split( '-' )[ 0 ].toLowerCase();
 		this.translations = window.ant_translations;
 		this.$log_container = $('#logArea');
 		this.recursion = 0;
 		this.cache_backend = '';
+		this.heartbeat = '';
 
 		if ( 'undefined' === typeof window.navigator.languages ) {
 			window.navigator.languages = [ window.navigator.language ];
@@ -78,6 +81,14 @@ class AntergosThemeUtils {
 	}
 
 
+	initialize_theme_heartbeat() {
+		this.log('Initializing theme heartbeat.');
+		this.heartbeat = setInterval(() => {
+			window.webkit.messageHandlers.GreeterBridge.postMessage('Heartbeat');
+		}, 5000);
+	}
+
+
 	setup_cache_backend() {
 		// Do we have access to localStorage?
 		try {
@@ -101,6 +112,7 @@ class AntergosThemeUtils {
 		if ('' === this.cache_backend) {
 			this.cache_backend = 'Cookies';
 		}
+		console.log(`this.cache_backend is: ${this.cache_backend}`);
 	}