diff --git a/html/index.html b/html/index.html
index 6424d29..46a03a3 100644
--- a/html/index.html
+++ b/html/index.html
@@ -931,10 +931,10 @@
                         <form id="altitude_filter_form">
                           <div class="infoBlockTitleText">Filter by altitude:</div>
                           <input id="altitude_filter_min" name="minAltitude" type="text" class="altitudeFilterInput" maxlength="5">
-                          <label for="minAltitude" class="altitudeUnit"></label>
+                          <label for="altitude_filter_min" class="altitudeUnit"></label>
                           <span> to </span>
                           <input id="altitude_filter_max" name="maxAltitude" type="text" class="altitudeFilterInput" maxlength="5">
-                          <label for="maxAltitude" class="altitudeUnit"></label>
+                          <label for="altitude_filter_max" class="altitudeUnit"></label>
                           <button class="formButton" type="submit">Filter</button>
                           <button class="formButton" id="altitude_filter_reset_button">Reset</button>
                         </form>