diff --git a/packages/react/src/components/CodeMirror6.jsx b/packages/react/src/components/CodeMirror6.jsx
index 00daf7d0..e1f55014 100644
--- a/packages/react/src/components/CodeMirror6.jsx
+++ b/packages/react/src/components/CodeMirror6.jsx
@@ -98,18 +98,17 @@ const visibleMiniLocations = StateField.define({
         // this is called every frame to show the locations that are currently active
         // we can NOT create new marks because the context.locations haven't changed since eval time
         // this is why we need to find a way to update the existing decorations, showing the ones that have an active range
-        const haps = new Map();
 
         for (let hap of e.value.haps) {
           for (let { start, end } of hap.context.locations) {
             let id = `${start}:${end}`;
-            if (!haps.has(id) || haps.get(id).whole.begin.lt(hap.whole.begin)) {
-              haps.set(id, hap);
+            if (!visible.haps.has(id) || visible.haps.get(id).whole.begin.lt(hap.whole.begin)) {
+              visible.haps.set(id, hap);
             }
           }
         }
 
-        visible = { atTime: e.value.atTime, haps };
+        visible = { atTime: e.value.atTime, haps: visible.haps };
       }
     }