diff --git a/app/views/projects/_edit_form.html.erb b/app/views/projects/_edit_form.html.erb
index eb2bdb605..e062f989b 100644
--- a/app/views/projects/_edit_form.html.erb
+++ b/app/views/projects/_edit_form.html.erb
@@ -270,7 +270,7 @@
       function addUsersToForm() {
          const userAlreadyAdded = usersInForm();
          const users = $(".data_user_added_modal");
-         var totalUserCount = users.length;
+         var totalUserCount = userAlreadyAdded.length;
          for(var i = 0; i < users.length; i += 1) {
             var netIdToAdd = users[i].firstChild.textContent;
             if (userAlreadyAdded.includes(netIdToAdd) === false) {
diff --git a/spec/system/project_spec.rb b/spec/system/project_spec.rb
index dad89d7c3..d40def688 100644
--- a/spec/system/project_spec.rb
+++ b/spec/system/project_spec.rb
@@ -305,13 +305,21 @@
         click_on "Create new project"
         expect(page.find("#non-editable-data-sponsor").text).to eq sponsor_user.uid
         fill_in_and_out "data_manager", with: data_manager.uid
+        expect(page).to have_content "No Data User(s) added"
+
+        # Launch the modal, trigger the validation, and then add a valid user
         click_on "+ Add User(s)"
         fill_in_and_out "data-user-uid-to-add", with: "notuser"
-        # shows the error
         expect(page.find("#data-user-uid-to-add_error").text).to eq "Invalid value entered"
-        # gets rid of the error
         fill_in_and_out "data-user-uid-to-add", with: read_only.uid
         expect(page.find("#data-user-uid-to-add_error", visible: false).text).to eq ""
+        click_on "Save changes"
+
+        # Launch the modal again and this time don't add any users
+        # (but we already had added some so we don't expect the "no data users" message)
+        click_on "+ Add User(s)"
+        click_on "Save changes"
+        expect(page).not_to have_content "No Data User(s) added"
       end
     end