diff --git a/opentech/static_src/src/javascript/main.js b/opentech/static_src/src/javascript/main.js
index 34772e074dc58b5544b49a17a562ab52469be5a3..8356fe85e95e43e5fcd325c6c5619b00a7019f0b 100644
--- a/opentech/static_src/src/javascript/main.js
+++ b/opentech/static_src/src/javascript/main.js
@@ -186,4 +186,19 @@
         }
     }
 
+
+    $('form').filter('.form__comments').submit(function (e) {
+        var $form = $(this);
+        var formValues = $form.serialize();
+        var previousValues = $form.attr('data-django-form-submit-last');
+
+        if (previousValues === formValues) {
+            // Previously submitted - don't submit again
+            e.preventDefault();
+        }
+        else {
+            $form.attr('data-django-form-submit-last', formValues);
+        }
+    });
+
 })(jQuery);