--- a/wp/wp-admin/js/password-strength-meter.js	Tue Jun 09 11:14:17 2015 +0000
+++ b/wp/wp-admin/js/password-strength-meter.js	Mon Oct 14 17:39:30 2019 +0200
@@ -18,6 +18,11 @@
 			if (password1 != password2 && password2 && password2.length > 0)
 				return 5;
 
+			if ( 'undefined' === typeof window.zxcvbn ) {
+				// Password strength unknown.
+				return -1;
+			}
+
 			var result = zxcvbn( password1, blacklist );
 			return result.score;
 		},
@@ -70,6 +75,6 @@
 		}
 	};
 
-	// Backwards compatibility.
+	// Back-compat.
 	passwordStrength = wp.passwordStrength.meter;
-})(jQuery);
\ No newline at end of file
+})(jQuery);