diff --git a/static/js/utils/massInput.js b/static/js/utils/massInput.js
index fa8e075bf..00713fbd8 100644
--- a/static/js/utils/massInput.js
+++ b/static/js/utils/massInput.js
@@ -25,6 +25,7 @@
 
   var MASS_INPUT_CELL_SELECTOR = '.massinput__cell';
   var MASS_INPUT_ADD_CELL_SELECTOR = '.massinput__cell--add';
+  var MASS_INPUT_SUBMIT_BUTTON_CLASS = 'massinput__submit-button';
   var MASS_INPUT_INITIALIZED_CLASS = 'mass-input--initialized';
 
   var massInputUtil = function(element) {
@@ -74,6 +75,12 @@
       }
 
       return function(event) {
+        // "unarm" submit buttons inside this massinput so browser
+        // uses correct submit button for form submission.
+        // contents of the massinput will be replaced either way,
+        // so unarming is no problem
+        unarmSubmitButtons();
+
         // check if event occured from either a mass input add/delete button or
         // from inside one of massinput's inputs (i.e. they are focused/active)
         var activeElement = element.querySelector(':focus, :active');
@@ -87,7 +94,7 @@
           return false;
         }
 
-        var submitButton = massInputCell.querySelector('button[type="submit"][name][value]');
+        var submitButton = massInputCell.querySelector('.' + MASS_INPUT_SUBMIT_BUTTON_CLASS);
         if (!submitButton) {
           return false;
         }
@@ -122,6 +129,14 @@
       };
     }
 
+    function unarmSubmitButtons() {
+      var buttons = Array.from(element.querySelectorAll('button[type="submit"][name][value]'));
+      buttons.forEach(function(button) {
+        button.setAttribute('type', 'button');
+        button.classList.add(MASS_INPUT_SUBMIT_BUTTON_CLASS);
+      });
+    }
+
     function processResponse(response) {
       element.innerHTML = response;