diff --git a/luhn-algorithm/index.html b/luhn-algorithm/index.html
index 06be2a1..5b6f93c 100644
--- a/luhn-algorithm/index.html
+++ b/luhn-algorithm/index.html
@@ -61,8 +61,8 @@
                     <!-- input field (in a container so that unwanted overflow from :before & :after is hidden) -->
                     <div class="mdc-text-field-container">
                         <div class="mdc-text-field mdc-text-field--outlined"  data-mdc-auto-init="MDCTextField">
-                            <input type="number" id="tf-outlined" class="mdc-text-field__input">
-                            <label for="tf-outlined" class="mdc-floating-label ">Your Number</label>
+                            <input type="number" id="number-input-field" class="mdc-text-field__input">
+                            <label for="number-input-field" class="mdc-floating-label ">Your Number</label>
                             <div class="mdc-notched-outline">
                                 <svg>
                                     <path class="mdc-notched-outline__path"/>