diff --git a/README.md b/README.md
index 5677c38..2936ade 100644
--- a/README.md
+++ b/README.md
@@ -337,6 +337,8 @@ v1.6.5 - Ensure the provided message is included when calling trace() in IE11
 
 v1.6.6 - Fix bugs in v1.6.5, which caused issues in node.js & IE < 9
 
+v1.6.7 - Fix a bug in environments with `window` defined but no `window.navigator`
+
 ## `loglevel` for enterprise
 
 Available as part of the Tidelift Subscription.
diff --git a/bower.json b/bower.json
index 1f8d558..cac803a 100644
--- a/bower.json
+++ b/bower.json
@@ -1,6 +1,6 @@
 {
   "name": "loglevel",
-  "version": "1.6.6",
+  "version": "1.6.7",
   "main": "dist/loglevel.min.js",
   "dependencies": {},
   "ignore": [
diff --git a/dist/loglevel.js b/dist/loglevel.js
index 40bdb91..5b92e58 100644
--- a/dist/loglevel.js
+++ b/dist/loglevel.js
@@ -1,4 +1,4 @@
-/*! loglevel - v1.6.6 - https://github.com/pimterry/loglevel - (c) 2019 Tim Perry - licensed MIT */
+/*! loglevel - v1.6.7 - https://github.com/pimterry/loglevel - (c) 2020 Tim Perry - licensed MIT */
 (function (root, definition) {
     "use strict";
     if (typeof define === 'function' && define.amd) {
@@ -14,7 +14,7 @@
     // Slightly dubious tricks to cut down minimized file size
     var noop = function() {};
     var undefinedType = "undefined";
-    var isIE = (typeof window !== undefinedType) && (
+    var isIE = (typeof window !== undefinedType) && (typeof window.navigator !== undefinedType) && (
         /Trident\/|MSIE /.test(window.navigator.userAgent)
     );
 
diff --git a/dist/loglevel.min.js b/dist/loglevel.min.js
index 5a56263..723b776 100644
--- a/dist/loglevel.min.js
+++ b/dist/loglevel.min.js
@@ -1,2 +1,2 @@
-/*! loglevel - v1.6.6 - https://github.com/pimterry/loglevel - (c) 2019 Tim Perry - licensed MIT */
-!function(a,b){"use strict";"function"==typeof define&&define.amd?define(b):"object"==typeof module&&module.exports?module.exports=b():a.log=b()}(this,function(){"use strict";function a(a,b){var c=a[b];if("function"==typeof c.bind)return c.bind(a);try{return Function.prototype.bind.call(c,a)}catch(b){return function(){return Function.prototype.apply.apply(c,[a,arguments])}}}function b(){console.log&&(console.log.apply?console.log.apply(console,arguments):Function.prototype.apply.apply(console.log,[console,arguments])),console.trace&&console.trace()}function c(c){return"debug"===c&&(c="log"),typeof console!==i&&("trace"===c&&j?b:void 0!==console[c]?a(console,c):void 0!==console.log?a(console,"log"):h)}function d(a,b){for(var c=0;c<k.length;c++){var d=k[c];this[d]=c<a?h:this.methodFactory(d,a,b)}this.log=this.debug}function e(a,b,c){return function(){typeof console!==i&&(d.call(this,b,c),this[a].apply(this,arguments))}}function f(a,b,d){return c(a)||e.apply(this,arguments)}function g(a,b,c){function e(a){var b=(k[a]||"silent").toUpperCase();if(typeof window!==i){try{return void(window.localStorage[l]=b)}catch(a){}try{window.document.cookie=encodeURIComponent(l)+"="+b+";"}catch(a){}}}function g(){var a;if(typeof window!==i){try{a=window.localStorage[l]}catch(a){}if(typeof a===i)try{var b=window.document.cookie,c=b.indexOf(encodeURIComponent(l)+"=");-1!==c&&(a=/^([^;]+)/.exec(b.slice(c))[1])}catch(a){}return void 0===j.levels[a]&&(a=void 0),a}}var h,j=this,l="loglevel";a&&(l+=":"+a),j.name=a,j.levels={TRACE:0,DEBUG:1,INFO:2,WARN:3,ERROR:4,SILENT:5},j.methodFactory=c||f,j.getLevel=function(){return h},j.setLevel=function(b,c){if("string"==typeof b&&void 0!==j.levels[b.toUpperCase()]&&(b=j.levels[b.toUpperCase()]),!("number"==typeof b&&b>=0&&b<=j.levels.SILENT))throw"log.setLevel() called with invalid level: "+b;if(h=b,!1!==c&&e(b),d.call(j,b,a),typeof console===i&&b<j.levels.SILENT)return"No console available for logging"},j.setDefaultLevel=function(a){g()||j.setLevel(a,!1)},j.enableAll=function(a){j.setLevel(j.levels.TRACE,a)},j.disableAll=function(a){j.setLevel(j.levels.SILENT,a)};var m=g();null==m&&(m=null==b?"WARN":b),j.setLevel(m,!1)}var h=function(){},i="undefined",j=typeof window!==i&&/Trident\/|MSIE /.test(window.navigator.userAgent),k=["trace","debug","info","warn","error"],l=new g,m={};l.getLogger=function(a){if("string"!=typeof a||""===a)throw new TypeError("You must supply a name when creating a logger.");var b=m[a];return b||(b=m[a]=new g(a,l.getLevel(),l.methodFactory)),b};var n=typeof window!==i?window.log:void 0;return l.noConflict=function(){return typeof window!==i&&window.log===l&&(window.log=n),l},l.getLoggers=function(){return m},l});
\ No newline at end of file
+/*! loglevel - v1.6.7 - https://github.com/pimterry/loglevel - (c) 2020 Tim Perry - licensed MIT */
+!function(a,b){"use strict";"function"==typeof define&&define.amd?define(b):"object"==typeof module&&module.exports?module.exports=b():a.log=b()}(this,function(){"use strict";function a(a,b){var c=a[b];if("function"==typeof c.bind)return c.bind(a);try{return Function.prototype.bind.call(c,a)}catch(b){return function(){return Function.prototype.apply.apply(c,[a,arguments])}}}function b(){console.log&&(console.log.apply?console.log.apply(console,arguments):Function.prototype.apply.apply(console.log,[console,arguments])),console.trace&&console.trace()}function c(c){return"debug"===c&&(c="log"),typeof console!==i&&("trace"===c&&j?b:void 0!==console[c]?a(console,c):void 0!==console.log?a(console,"log"):h)}function d(a,b){for(var c=0;c<k.length;c++){var d=k[c];this[d]=c<a?h:this.methodFactory(d,a,b)}this.log=this.debug}function e(a,b,c){return function(){typeof console!==i&&(d.call(this,b,c),this[a].apply(this,arguments))}}function f(a,b,d){return c(a)||e.apply(this,arguments)}function g(a,b,c){function e(a){var b=(k[a]||"silent").toUpperCase();if(typeof window!==i){try{return void(window.localStorage[l]=b)}catch(a){}try{window.document.cookie=encodeURIComponent(l)+"="+b+";"}catch(a){}}}function g(){var a;if(typeof window!==i){try{a=window.localStorage[l]}catch(a){}if(typeof a===i)try{var b=window.document.cookie,c=b.indexOf(encodeURIComponent(l)+"=");-1!==c&&(a=/^([^;]+)/.exec(b.slice(c))[1])}catch(a){}return void 0===j.levels[a]&&(a=void 0),a}}var h,j=this,l="loglevel";a&&(l+=":"+a),j.name=a,j.levels={TRACE:0,DEBUG:1,INFO:2,WARN:3,ERROR:4,SILENT:5},j.methodFactory=c||f,j.getLevel=function(){return h},j.setLevel=function(b,c){if("string"==typeof b&&void 0!==j.levels[b.toUpperCase()]&&(b=j.levels[b.toUpperCase()]),!("number"==typeof b&&b>=0&&b<=j.levels.SILENT))throw"log.setLevel() called with invalid level: "+b;if(h=b,!1!==c&&e(b),d.call(j,b,a),typeof console===i&&b<j.levels.SILENT)return"No console available for logging"},j.setDefaultLevel=function(a){g()||j.setLevel(a,!1)},j.enableAll=function(a){j.setLevel(j.levels.TRACE,a)},j.disableAll=function(a){j.setLevel(j.levels.SILENT,a)};var m=g();null==m&&(m=null==b?"WARN":b),j.setLevel(m,!1)}var h=function(){},i="undefined",j=typeof window!==i&&typeof window.navigator!==i&&/Trident\/|MSIE /.test(window.navigator.userAgent),k=["trace","debug","info","warn","error"],l=new g,m={};l.getLogger=function(a){if("string"!=typeof a||""===a)throw new TypeError("You must supply a name when creating a logger.");var b=m[a];return b||(b=m[a]=new g(a,l.getLevel(),l.methodFactory)),b};var n=typeof window!==i?window.log:void 0;return l.noConflict=function(){return typeof window!==i&&window.log===l&&(window.log=n),l},l.getLoggers=function(){return m},l});
\ No newline at end of file
diff --git a/package.json b/package.json
index aaa1444..5b59136 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "loglevel",
   "description": "Minimal lightweight logging for JavaScript, adding reliable log level methods to any available console.log methods",
-  "version": "1.6.6",
+  "version": "1.6.7",
   "homepage": "https://github.com/pimterry/loglevel",
   "author": {
     "name": "Tim Perry",