diff --git a/themes/bootstrap3/js/common.js b/themes/bootstrap3/js/common.js
index dc573cab6c0324f3f6cbb1c0d8c43bd281a3dc17..554ed519f2a45adafcf480d7239c22113ebedb7e 100644
--- a/themes/bootstrap3/js/common.js
+++ b/themes/bootstrap3/js/common.js
@@ -163,7 +163,7 @@ function phoneNumberFormHandler(numID, regionCode) {
 
 // Setup captchas after Google script loads
 function recaptchaOnLoad() {
-  if (grecaptcha) {
+  if (typeof grecaptcha !== 'undefined') {
     var captchas = $('.g-recaptcha:empty');
     for (var i = 0; i < captchas.length; i++) {
       captchas[i].dataset.captchaId = grecaptcha.render(captchas[i], captchas[i].dataset);
diff --git a/themes/bootstrap3/js/lightbox.js b/themes/bootstrap3/js/lightbox.js
index 350dc71f491c43863881ab4c0a2569f2990493e3..018b171d27b18c7270ee0efee8da2f664efad3c0 100644
--- a/themes/bootstrap3/js/lightbox.js
+++ b/themes/bootstrap3/js/lightbox.js
@@ -226,7 +226,7 @@ VuFind.register('lightbox', function Lightbox() {
     var form = event.target;
     var data = $(form).serializeArray();
     // Check for recaptcha
-    if (grecaptcha) {
+    if (typeof grecaptcha !== 'undefined') {
       var recaptcha = $(form).find('.g-recaptcha');
       if (recaptcha.length > 0) {
         data.push({ name: 'g-recaptcha-response', value: grecaptcha.getResponse(recaptcha.data('captchaId')) });
@@ -277,7 +277,7 @@ VuFind.register('lightbox', function Lightbox() {
       method: $(form).attr('method') || 'GET',
       data: data
     }).done(function recaptchaReset() {
-      if (grecaptcha) {
+      if (typeof grecaptcha !== 'undefined') {
         grecaptcha.reset($(form).find('.g-recaptcha').data('captchaId'));
       }
     });
diff --git a/themes/bootstrap3/js/record.js b/themes/bootstrap3/js/record.js
index 786bc8937d605d4fdddfd188d5097617adc898b2..f247c3a631f8b5a046c0413254e73201cee2f860 100644
--- a/themes/bootstrap3/js/record.js
+++ b/themes/bootstrap3/js/record.js
@@ -96,7 +96,7 @@ function registerAjaxCommentRecord() {
       id: id,
       source: recordSource
     };
-    if (grecaptcha) {
+    if (typeof grecaptcha !== 'undefined') {
       var recaptcha = $(form).find('.g-recaptcha');
       if (recaptcha.length > 0) {
         data['g-recaptcha-response'] = grecaptcha.getResponse(recaptcha.data('captchaId'));
@@ -113,7 +113,7 @@ function registerAjaxCommentRecord() {
       refreshCommentList($tab, id, recordSource);
       $(form).find('textarea[name="comment"]').val('');
       $(form).find('input[type="submit"]').button('loading');
-      if (grecaptcha) {
+      if (typeof grecaptcha !== 'undefined') {
         grecaptcha.reset($(form).find('.g-recaptcha').data('captchaId'));
       }
     })