diff --git a/src/UiPopover.vue b/src/UiPopover.vue
index 5065d8de..fdcedcaa 100644
--- a/src/UiPopover.vue
+++ b/src/UiPopover.vue
@@ -15,7 +15,11 @@
 
 <script>
 import classlist from './helpers/classlist';
-import Drop from 'tether-drop';
+
+let Drop;
+if (typeof window !== 'undefined') {
+    Drop = require('tether-drop');
+}
 
 export default {
     name: 'ui-popover',
diff --git a/src/UiTooltip.vue b/src/UiTooltip.vue
index ecd479ad..02c8fa6b 100644
--- a/src/UiTooltip.vue
+++ b/src/UiTooltip.vue
@@ -5,8 +5,11 @@
 </template>
 
 <script>
-import Tooltip from 'tether-tooltip';
 import UUID from './helpers/uuid';
+let Tooltip;
+if (typeof window !== 'undefined') {
+    Tooltip = require('tether-tooltip');
+}
 
 export default {
     name: 'ui-tooltip',
diff --git a/src/config.js b/src/config.js
index e8df221f..57ae4898 100644
--- a/src/config.js
+++ b/src/config.js
@@ -55,7 +55,7 @@ const config = {
 
 export class KeenUiConfig {
     constructor() {
-        this.data = merge(config, window.KeenUiConfig ? window.KeenUiConfig : {});
+        this.data = merge(config, (typeof window !== 'undefined' && window.KeenUiConfig) ? window.KeenUiConfig : {});
     }
 
     set(config = {}) {
diff --git a/src/helpers/modality.js b/src/helpers/modality.js
index 17fe3f59..564b6663 100644
--- a/src/helpers/modality.js
+++ b/src/helpers/modality.js
@@ -2,93 +2,96 @@
  * Adapted from https://github.com/alice/modality
  * Version: 1.0.2
  */
-document.addEventListener('DOMContentLoaded', () => {
-    let hadKeyboardEvent = false;
-    const keyboardModalityWhitelist = [
-        'input:not([type])',
-        'input[type=text]',
-        'input[type=number]',
-        'input[type=date]',
-        'input[type=time]',
-        'input[type=datetime]',
-        'textarea',
-        '[role=textbox]',
-        '[supports-modality=keyboard]'
-    ].join(',');
-
-    let isHandlingKeyboardThrottle;
-
-    const matcher = (() => {
-        const el = document.body;
-
-        if (el.matchesSelector) {
-            return el.matchesSelector;
-        }
-
-        if (el.webkitMatchesSelector) {
-            return el.webkitMatchesSelector;
-        }
-
-        if (el.mozMatchesSelector) {
-            return el.mozMatchesSelector;
-        }
-
-        if (el.msMatchesSelector) {
-            return el.msMatchesSelector;
-        }
-
-        console.error('Couldn\'t find any matchesSelector method on document.body.');
-    })();
-
-    const disableFocusRingByDefault = function () {
-        const css = 'body:not([modality=keyboard]) :focus { outline: none; }';
-        const head = document.head || document.getElementsByTagName('head')[0];
-        const style = document.createElement('style');
-
-        style.type = 'text/css';
-        style.id = 'disable-focus-ring';
-
-        if (style.styleSheet) {
-            style.styleSheet.cssText = css;
-        } else {
-            style.appendChild(document.createTextNode(css));
-        }
-
-        head.insertBefore(style, head.firstChild);
-    };
-
-    const focusTriggersKeyboardModality = function (el) {
-        let triggers = false;
-
-        if (matcher) {
-            triggers = matcher.call(el, keyboardModalityWhitelist) &&
+
+if (typeof window !== 'undefined') {
+    document.addEventListener('DOMContentLoaded', () => {
+        let hadKeyboardEvent = false;
+        const keyboardModalityWhitelist = [
+            'input:not([type])',
+            'input[type=text]',
+            'input[type=number]',
+            'input[type=date]',
+            'input[type=time]',
+            'input[type=datetime]',
+            'textarea',
+            '[role=textbox]',
+            '[supports-modality=keyboard]'
+        ].join(',');
+
+        let isHandlingKeyboardThrottle;
+
+        const matcher = (() => {
+            const el = document.body;
+
+            if (el.matchesSelector) {
+                return el.matchesSelector;
+            }
+
+            if (el.webkitMatchesSelector) {
+                return el.webkitMatchesSelector;
+            }
+
+            if (el.mozMatchesSelector) {
+                return el.mozMatchesSelector;
+            }
+
+            if (el.msMatchesSelector) {
+                return el.msMatchesSelector;
+            }
+
+            console.error('Couldn\'t find any matchesSelector method on document.body.');
+        })();
+
+        const disableFocusRingByDefault = function () {
+            const css = 'body:not([modality=keyboard]) :focus { outline: none; }';
+            const head = document.head || document.getElementsByTagName('head')[0];
+            const style = document.createElement('style');
+
+            style.type = 'text/css';
+            style.id = 'disable-focus-ring';
+
+            if (style.styleSheet) {
+                style.styleSheet.cssText = css;
+            } else {
+                style.appendChild(document.createTextNode(css));
+            }
+
+            head.insertBefore(style, head.firstChild);
+        };
+
+        const focusTriggersKeyboardModality = function (el) {
+            let triggers = false;
+
+            if (matcher) {
+                triggers = matcher.call(el, keyboardModalityWhitelist) &&
                 matcher.call(el, ':not([readonly])');
-        }
+            }
 
-        return triggers;
-    };
+            return triggers;
+        };
 
-    disableFocusRingByDefault();
+        disableFocusRingByDefault();
 
-    document.body.addEventListener('keydown', () => {
-        hadKeyboardEvent = true;
+        document.body.addEventListener('keydown', () => {
+            hadKeyboardEvent = true;
 
-        if (isHandlingKeyboardThrottle) {
-            clearTimeout(isHandlingKeyboardThrottle);
-        }
+            if (isHandlingKeyboardThrottle) {
+                clearTimeout(isHandlingKeyboardThrottle);
+            }
 
-        isHandlingKeyboardThrottle = setTimeout(() => {
-            hadKeyboardEvent = false;
-        }, 100);
-    }, true);
+            isHandlingKeyboardThrottle = setTimeout(() => {
+                hadKeyboardEvent = false;
+            }, 100);
+        }, true);
 
-    document.body.addEventListener('focus', e => {
-        if (hadKeyboardEvent || focusTriggersKeyboardModality(e.target)) {
-            document.body.setAttribute('modality', 'keyboard');
-        }
-    }, true);
+        document.body.addEventListener('focus', e => {
+            if (hadKeyboardEvent || focusTriggersKeyboardModality(e.target)) {
+                document.body.setAttribute('modality', 'keyboard');
+            }
+        }, true);
 
-    document.body.addEventListener('blur', () => {
-        document.body.removeAttribute('modality');
-    }, true);
-});
+        document.body.addEventListener('blur', () => {
+            document.body.removeAttribute('modality');
+        }, true);
+    });
+}