diff --git a/static/poopGraph.js b/static/poopGraph.js
index 5b3f7c4..c39c13a 100644
--- a/static/poopGraph.js
+++ b/static/poopGraph.js
@@ -5,7 +5,7 @@ const cutSpikesInput = document.getElementById('cutSpikes');
 const hashParams = new URLSearchParams(window.location.hash.substring(1));
 startInput.value = hashParams.get('start');
 endInput.value = hashParams.get('end');
-cutSpikesInput.checked = hashParams.get('cutSpikes') === 'true';
+cutSpikesInput.checked = hashParams.get('cutSpikes') !== 'false';
 
 const SPIKE_PERCENTILE = 95;
 const Y_ROUNDING = 500;
@@ -303,8 +303,8 @@ function plot(data) {
         if (end !== '') {
             params.set('end', end);
         }
-        if (cutSpikesInput.checked) {
-            params.set('cutSpikes', 'true');
+        if (!cutSpikesInput.checked) {
+            params.set('cutSpikes', 'false');
         }
         window.location.hash = params.toString();
     };