diff --git a/app/assets/javascripts/judge.js b/app/assets/javascripts/judge.js
index e9a413e..40d963f 100644
--- a/app/assets/javascripts/judge.js
+++ b/app/assets/javascripts/judge.js
@@ -256,7 +256,12 @@
   judge.eachValidators = {
     // ActiveModel::Validations::PresenceValidator
     presence: function(options, messages) {
-      return closed(this.value.length ? [] : [messages.blank]);
+      if (this.type === 'radio') {
+        var is_selected = root.document.querySelectorAll('[name="'+this.name+'"]:checked').length;
+        return closed(is_selected ? [] : [messages.blank]);
+      } else {
+        return closed(this.value.length ? [] : [messages.blank]);
+      }
     },
 
     // ActiveModel::Validations::LengthValidator
diff --git a/spec/javascripts/judge-spec.js b/spec/javascripts/judge-spec.js
index 33fdeaa..11353f1 100644
--- a/spec/javascripts/judge-spec.js
+++ b/spec/javascripts/judge-spec.js
@@ -260,6 +260,25 @@ describe('judge', function() {
         el.value = 'foo';
         expect(validator({}, { blank: 'Must not be blank' })).toBeValid();
       });
+      it('returns invalid Validation if radio has no selection', function() {
+        el.type  = 'radio'
+        el.name  = 'radio_group'
+        el.value = 'option1'
+        // eachValidators.presence for radio btns rely on querySelectorAll
+        // so we have to add the el to the body
+        document.body.appendChild(el);
+        expect(validator({}, { blank: 'Must not be blank' })).toBeInvalid();
+      });
+      it('returns valid Validation if radio has selection', function() {
+        el.type    = 'radio'
+        el.name    = 'radio_group'
+        el.value   = 'option1'
+        el.checked = true;
+        // eachValidators.presence for radio btns rely on querySelectorAll
+        // so we have to add the el to the body
+        document.body.appendChild(el);
+        expect(validator({}, { blank: 'Must not be blank' })).toBeValid();
+      });
     });
 
     describe('length', function() {